1. Introduction

With the open policy and frequent communication with international countries, Chinese people have more opportunities to use English. At the same time, writing is one of the most important ways of outputting. Listening, speaking, reading and writing are the basic four skills of language learning which can#8217;t be apart .Writing skill has often been neglected in language learning in schools, therefore, nowadays undergraduates#8217; English writing ability is a weak link. We should put emphasis on the improvement of their writing ability and strive to change this situation. This paper attempts to introduce some important basic writing theories as well as techniques used in composing writings. In addition, I will offer several kinds of cases written by different undergraduates, studying and analyzing their writing characteristics to find out effective methods to help undergraduates improve their English writing ability and writing quality.

Nowadays, many undergraduates don#8217;t really understand the true importance of writing and do not master skills of writing, as they are even unfamiliar with basic writing theories. They just consider writing as one part in CET4, CET6, TEM4 etc. As far as I am concerned, writing has deeper importance in many ways. Improving our ability of using words is a basic function of writing. Moreover, writing is an effective way to enlarge our vocabulary. Different compositions we write need different vocabularies. Therefore, the more compositions we write, the more vocabularies we get. At the same time, it is helpful to enlarge our reading. Writing makes great contribution to our logical thinking and analysis ability. For one thing, to write a good composition, we must collect and arrange writing materials systematically so that we can realize what is essential and what is not so important. In the process of dealing with materials, we are also learning to analyze and deal with the different problems. For another, it is also a process to practice our own thinking ability and form different thoughts. By dealing with all kinds of compositions, we can get in touch with more thoughts and become wiser.

2. Literature review

2.1 Previous studies on writing theories at home

English writing strategies are some methods and means used consciously to realize and have access to English writing learning objectives. Nowadays, people put increasingly more and more attention on the study of English learning strategies, and the number of people who specializes in researching the study of English writing strategies accordingly increased rapidly. The content of strategies has already covered all main aspects of English Writing--- conception, layout, word choice, feedback and modification, cultural awareness, and differences between native language and target language, researched by Huang,Ren(2009) and Li, Guanyi(2009) in Shanghai. They also made effort to discussing about how to strengthen the ability of training and teaching writing strategies , analyzing the usage and result of writing strategies in the view of CET4, CET6, introducing strategies related to relating discipline relations.

2.2 Previous studies on writing theories abroad

According to Teacher#8217;s Hand book(2010) conducted by Shrum, J. L.,Glisan,E.W. we can find students are deeply influenced by mother language(L1) when writing L2 compositions. They can#8217;t organize English to express their thoughts very well. In many cases, the hardest thing for a student concerning writing is to get started with the entire writing process. What to write about is also a quite common problem. The process of collecting information and coming up with ideas is not easy for everyone. What#8217;s more, Students lack of interests may be due to their poor language input, such as, correct grammar structure, enough vocabularies or foreign language reading. Students can#8217;t use conjunction freely or make correctly use of tense etc.

In the past few decades, English writing have successfully attracted a lot of attentions and more and more scholars come into notice the necessities of studying the strategies of improving the ability of writing. However, there still exits some problems in the previous studies.