In this paper, the favourable conclusions are obtained by means of climatic st atistical diagnosis which uses a cluster analysis of wave vector patterns for da ily extreme low temperature during winter and daily extreme high temperature dur ing summer in Jiangsu.The results show： (1) because of affect of the summer wea ther circulation pattern and features of rainfall on daily maximum high temperat ure during summer(6～7 monthly) in Jiangsu,the vibration patterns of the extreme temperatures have different characters during summer and winter in Jiangsu ; (2) the interannual variabilities of the wave vector patterns of the extreme tempera t ures during summer and winter have some different features ,for example, in Shan ghai.