| Writing, as a combination of almost every aspect of language knowledge, is really a good mirror that reflects students' mastery of a language. In English writing Chinese college students make various kinds of errors, which seems a never-ending phenomenon for the students and a thorny problem for teachers to solve. What types of errors do the college students often make in their English writing? Is there any regularity? As is well known, English and Chinese belong to two different language families, and great differences exist in various aspects such as morphology, syntax and culture. Thus, what types of errors are caused by L1 interference? And how does mother tongue function? Those questions are the major concern of this thesis.Error analysis, transfer theory and contrastive analysis of English and Chinese are illustrated in the second chapter. Then a data-based analysis of text errors is made. 100 compositions are randomly selected from 490 first-year non-English majors of Lanzhou University. Through an integration of quantitative and qualitative analysis, text errors are analysed in linguistic categories and error sources to find their distribution and frequency. It is found that there is no clearcut division between errors traceable to L1 interference and those that are independent of L1 interference; many intralingual errors are caused by L1 interference indirectly. Errors caused by L1 interference are analyzed through contrastive analysis between English and Chinese in detail.Finally, some useful proposals are put forward for English teaching in light of the research findings. |