Researches have been done on buffer space of buffer type conical telescopic crown retainer as well as displacement of denture support tissues and stress distribution by means of finite element analysis.The result shows that the stress value of subbasal tissues apparently surpassed that of periodontal tissues when the loadr was within 130N,However,after the loading force reaching 130N,the occlusal space between internal & external crown of retainers dissappeared.The stress value of abutment pesiodontal support tissues increased obviously and the differential value of stress between these two kind of support tissues of denture decreased.