Abstract:In order to realize the situation of the surface humid in Jiangsu province，a dr y wet index，including the impact of both surface air temperature and　precipit ation on the potential evaporation，is established by using monthly mean tempera ture and monthly precipitation data of 60 meteorological stations in Jiangsu pro vince from 1961-2005. The index is defined as Hi=P/Pe (P is the monthly total of precipitation，Pe is the potential evaporation from air　temperature). Analysis of the index by Mann Kendall method，the inter annual variation，decadal vari ation and the seasonal differences of the surface humid index，precipitation and temperature over Jiangsu province are analyzed．The warming impact on th e surface dryness/wetness state is studied．The geographical distribution and tr end of surface humid index are given in the areas．The results indicate that the inter-annual variation of surface humid index over northern Jiangsu is contrary to that of the south region of Jiangsu．There exists a relationship between the drying trend and the warming impact in north and middle part of Jiangsu provinc e. The obvious wetting trend doesn't occur in the regions where the precipitatio n increases in some part of south Jiangsu．Also，the results show that the dryi ng trend of Jiangsu province generally occurred in spring and autumn．