1.Introduction With the rapid development of science and technology, especially the constant emerging of state-of-the-art smart phones, more and more people tend to use them to deal with almost everything in their daily life because of the convenience brought by smart phones. Recently, a large number of learning APPs are developed to meet modern learners#8217; needs. People can learn anything they are interested in anywhere and anytime, which help improve the education ubiquitous environment. English learning APPs are the most popular ones which are used by English learners, especially university students. Hence, people have entered into an era of M-learning (mobile learning). 1.1Need for the study With the updating of smart phones, dramatic changes have taken place in people#8217;s M-learning modules, which provide a more efficient platform for learners. Many English learning apps are designed for students of all ages and levels. Some are designed for group activities. Others support independent learning. Still others are ideal for homework. Meanwhile, they are also designed to assist various kinds of language skills improvement, such as listening and speaking, reading, writing, vocabulary, grammar, translation, and comprehensive skills. Due to the portability of mobile phones and the individuality, interactivity, ubiquity and immediacy of learning APPs, mobile learning makes a difference to autonomous learning. The days when teachers would not permit the use of mobile devices are gone. Therefore, it is urgent to investigate university students' use of English learning apps. 1.2 Research purpose Since smart phones are so common and students want to use them because there are so many great apps which can#160;address personalized English-learning objectives. When they use English learning apps, students interact with language differently than in a traditional classroom. They act on or respond to something, instead of just listening to new information or reading some materials. Some teachers find that apps can help students become more actively involved in learning. These are all really good reasons for why instructors should help students to use some apps. This paper is to investigate students#8217; use of English learning APPs. Then, some useful implications will be drawn out and make contributions to the effectiveness of university English teaching and learning. 2. Literature Review 2.1Theoretical foundations Dramatic changes had taken place in teaching and learning theory in 1980s, student-centered teaching displaced teacher-centered method. Constructivism is a psychological theory of learning, the core idea of constructivism is that the student aims to resolve the problems, he/she will create an object (can be material, or can be calculated), during this process, they change their implicit thought into explicit. There are two schools of the constructivism theory #8212; cognitive constructivism and social constructivism. Cognitive constructivism is a psychological theory which developed by a representative researcher of cognitive constructivism Jean Piaget (1970), which means that the language is processed by human mind. There are four stages in cognitive development, and each consists of a constant effort to adapt to the environment in terms of assimilation (the interpretation of events within the existing cognitive structure) and accommodation (changing the cognitive structure to make sense of the environment). He also believes that learning is a process of constructing useful representations which are based on the former experiences and adapting the existing mental models to accommodate new experience. The representative researcher of social constructivism is Vygotsky, a Russian psychologist in the 1930s. He pays more heed on the function of social environment which plays an important role in constructing the learner#8217;s knowledge system. In his opinion, human beings couldn#8217;t separate themselves from the social environment. Meanwhile, both language and social context can have some influence on people#8217;s explanation of the social fact. It is believed that both cognitive constructivism and social constructivism play a significant part in language learning. Constructivism also has a close connection with mobile language learning. Mobile learning is a sort of autonomous learning and the major principles that autonomy in language learning has borrowed from constructivism is ”active” learning (Benson, 2005). Henri Holec (1981) first introduces the term of ”autonomous learning” into language teaching area, ”learner autonomy is the students#8217; ability to self-manage language learning. Specifically speaking, it is the ability that learners can determine their own learning objectives, keep control the pace of learning, decide their own learning methods and strategies and monitor the acquisition process.” Dickinson (1987:11) accepts the definition of autonomy as a situation in which the learner is totally responsible for all the decisions concerning his/her learning. Chinese researcher Pang Weiguo (2001) defines the autonomous learning as establishing on the basis of the development of self-awareness ”can learn”; building students#8217; intrinsic motivation on the basis of ”want to learn” which are based on some learning strategies that the students have mastered. In conclusion, both constructivism and autonomous learning emphasize that teaching should be learner centered and the teacher should be a consultant, a facilitator, and a tutor. Meanwhile the learners should be active in thinking, monitoring and constructing the meaningful knowledge by themselves. In the information age, learners should combine the flexibility and mobility of English learning APPs with the autonomy and regulatory of autonomous learning together so that the learner can become the most important benefactor. 2.2 Related empirical studies Nowadays, using English learning software to study English has become a trend, especially among the students. Many scholars have also conducted a number of studies on mobile English learning. Some scholars summarized the tendency of the use of various English learning APPs by collecting the downloading times of APPs on a certain type of mobile device. By testing and comparing the applications with more than 100,000 downloads on Vivo X7, a smart phone which is commonly used in China, He Shuman (2017) supplies data and information of the English learning applications as reference for users. The results of the study showed that English listening and speaking skills training APPs with more than 100,000 downloads ranked the first, and the second was comprehensive English skills training APPs, which consisted of listening, speaking, reading and writing skills training. Words reciting APPs were in the third place. Dictionary APPs ranked the fourth. APPs of reading skills training, grammar skills training, and writing skills training are lower in the number of downloads. The data showed that users payed more attention to the improvement of listening and speaking ability, but paid less attention to the long-term input accumulation of English and the training of language usage. It can be found that the main purpose of using APPs for English learner is to cooperate with the examination-oriented education. Most of English Learning APPs provide exercises and instant performance feedback, which allow users to quickly obtain their learning status and enhance their self-confidence in learning. What#8217;s more, these APPs do motive and improve their English study. Some scholars studied the use of a certain kinds of software to figure out whether the software could improve students#8217; English ability in certain aspect or how to improve this ability through this software. Lv Shuang (2015), for example, has studied whether Liulishuo could improve students#8217; spoken English and how it could be applied to college English classes. It revealed that under the guidance of teachers, ”Liulishuo”, an English learning APP which combined both entertainment and autonomy learning, will bring a brand-new experience to oral English learning. In the absence of English environment, reasonable use of software to help students to do a lot of listening and reading training is worthy of promotion These two researches both observed the necessity of the application of English learning APPs, but their researches were both limited in some certain mobile device or a certain kind of App. Other scholars have studied the factors that have effects on university students' behavioral intention in mobile English learning. For example, Ji Lu (2016), based on the technical acceptance model, analyzed the valid data from The mobile English learning intention questionnaire of students in Chongqing University. According to the relevant criteria of the parameter, it is concluded that the model constructed by the study is complete and acceptable. The key factors that significantly affect university students#8217; behavioral intention in mobile English learning has been found. Zhang Ting et. al. (2017), on the basis of the TAM technical acceptance model, carried out the analysis of the users#8217; behavior towards the English learning APPs. It can be concluded that the effectiveness of the English learning app is related to the user#8217;s satisfaction. Besides, social influence is another factor that affects users#8217; choice of English learning APPs. These researches mainly studied the factors that influence users#8217; behavior towards the mobile English learning APPs. The effectiveness, users#8217; satisfaction, social influence, the using will and loyalty are all included in the factors. 2.3 Problems in the previous studies Among the present studies, some are confined to English learning APPs on a certain king of mobile device or a certain kind of English learning APP, some analyze factors influencing the users#8217; behavioral intention of mobile English learning. The experimental subjects in previous studies are either English major students or non-English majors. Although some studies have obtained some enlightenment to oral English teaching, students need to acquire comprehensive English ability in order to meet the needs of the daily communication in English. This study will conduct a research among university students mainly about their attitudes toward English learning APPs, the frequency, strategy, preference and the effects of their use of English learning APPs. Moreover, some useful implications will be offered, so as to improve the efficiency of English learning in universities. References Cavus, N., Ibrahim, D. (2008). M‐learning: An experiment in using SMS to support learning new English language words. British Journal of Educational Technology, 40, 78-91. Chen, Y. N. (2010). Speech recognition technique in oral English Learning. Master#8217;s dissertation, Shanghai Jiao Tong University. Furi#243;, D. et al. (2014). Mobile learning vs. traditional classroom lessons: a comparative study. 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朱晶(2015), 基于TAM的研究生移动学习影响因素研究, 硕士学位论文，山东师范大学。