With a self-paced phrase-by-phrase reading experiment,this research investigates how second language(L2)learners use syntactic knowledge of the morph-syntactic features and syntactic structure during online co-reference processing of English pronouns him and her.The results indicate that both the gender of binding-inaccessible antecedents and binding-accessible antecedents influence the online resolution of L2 pronouns.Conclusion can be drawn that word frequency,the morph-syntactic features and syntactic structure impact the online L2 pronoun resolution.Furthermore,the antecedent retrieval in the working memory is identified from the right to the left.