Non-native-English-speaking (NNS) students' silent and reticent behaviour,which make the EAP (English for Academic Purpose) class seem ineffective and boring,might be unfavourably evaluated by a native English speaker of Western culture. By giving an overview of international students' inactive participation in the classroom,which prevents teachers from Western culture making a proper judgement on study mood,this paper will explore culturally based perceptions of international students' silent and reticent behaviour in the EAP classroom,and analyse the reasons behind NNS students' silent reaction.