This paper aims to investigate what types of paraphrasing are the most and the least frequently attempted by Korean L2 writers and to examine whether the tendency is affected by L2 writers’ English proficiency. A total of 50 summary protocols were collected from 50 college students and analyzed through the discourse analysis program, CLAN. It has been found that when attempting to paraphrase, Korean L2 summary writers tend to resort to minimal modification such as deleting, adding, or replacing vocabulary using synonyms; they are reluctant to modify substantially by combining or transforming sentence structures. The frequency of using more substantial syntactic modification increases as their proficiency improves. However, the overall tendency still remains that syntactic modification is much less used than lexical modification across the differing proficiency groups. Thus, instruction of paraphrasing skills is recommended particularly for less proficient L2 writers since it encourages them to use syntactic and lexical knowledge for communicative purposes. It is also suggested that paraphrasing tasks will be valid writing tasks for assessing syntactic and lexical knowledge in use.