Abstract: This study examined the relationship between second language learners’ proficiency and their second language learning in Collaborative dialogues in a quantitative way.48 learners with different levels of language proficiency were assigned into 3 groups：the high-high group,the high-low group and the low-low group.There were 16 subjects (8 pairs) in each group.All the subjects finished a five-stage collaborative writing task through different combinations.The results showed that the subjects’ proficiency had a significant effect on the output of their Language-related episodes (LREs) and their second language learning within the framework of collaborative dialogues.Furthermore,the higher proficiency the subjects had,the more output their LREs produced and the more effective their second language learning would be.

Key words: Collaborative dialogue, Linguistic Proficiency, LRE, Second language learning