Writing, as an advanced model of output, not only conveys the subject but also realizes the communication between readers and writers. Metadiscourse can help writers arrange and organize the discourse to influence readers' understanding of the text and their attitude towards its content. Taking writing samples of College English Test Band 4 (CET-4) as corpus, the research aims to explore the use of metadiscoure markers in high score writing group (HG) and low score writing group (LG). The research questions to be addressed in the study are as follows: 1) What are the similarities and differences between the two groups in the quantity and the types of metadiscourse markers? 2) What are the similarities and differences between the two groups in choosing metadiscourse markers? 3) What's the overall distribution of the inappropriately used metadiscourse markers in two groups? The research results show that there is a positive relation between proper use of metadiscourse markers and writing quality. This paper puts forward the strategies of improving the students' ability in the proper use of metadiscourse markers in English writing teaching.