Abstract: Based on the average precipitation data of 84 weather stations in Hunan province from 1981 to 2010,using the method of geostatistics and geographic information system（GIS）,the spatial variation of annual precipitation in Hunan province was analysed,and its spatial pattern was studied using ordinary Kriging interpolation method for its local linear optimal unbiased estimation. The results showed that the annual average precipitation in Hunan province conforms to the spherical model and had a strong spatial autocorrelation. The anisotropy analysis of the four directions of 30°,75°,120° and 165° were selected,the goodness of fit R² of the variogram in the four directions was lower,and isotropic at 30° and 75°. While in the direction of 120° and 165° were anisotropic. The spatial distribution of annual average precipitation in Hunan province was obtained by ordinary Kriging interpolation. It was found that there was a small spatial difference in average annual precipitation in Hunan province,with a decreasing trend from east to west as a whole. However,the high value area appeared at Yiyang city in central Hunan province.

Key words: geostatistics, precipitation, spatial variability, Hunan province