The relation between isotopic compositions of precipitation and surface air temperature provides an unique tool for paleoclimate studies. Ananysis was conducted of monthly and annual mean d18O content of precipitation and surface air temperature for spatial and a fixed location by using the the data of China (1985~2002) in Global Network of Isotopes in Precipitation (GNIP) Database.This study shows that there is a positive correlation between d18O of precipitation and surface air temperature for those stations whose latitude is higher than 34°~36°N. The seasonal d18O-temperature gradient derived from the monthly data of 12 stations in northern China is about 0.34‰°C-1. The d18O-temperature gradient, however, derived from the longterm annual mean data of 13 stations,, is about 0.52‰°C -1 which is substantially larger than the seasonal gradient. This longterm annual d18O-temperature gradient could be used as the isotope thermometer for palaeoclimate reconstruction in mid- and high-latitude regions in China.