Abstract: Based on the version 3.0 basic meteorology historical dataset released by National Meteorological Information Centre (NMIC), China Meteorological Administration, at the end of 2012, inhomogeneity test of annual precipitation series of 2342 stations has been launched using Standard Normal Homogeneity Test (SNHT) method. The nearby stations with high correlation coefficients with candidate station and high data complement are chosen to construct reference series by correlation coefficient weighted average and first difference method. The results which depend on the reference series calculation method would be cut. Metadata is the most valuable evidence of change points, fortunately NMIC has been collecting historical information of meteorological observation stations over China for several years and a junior version of metadata could be employed in this study. Ninety-eight inhomogeneous stations are found, accounting for 4.2% of all stations. The annual precipitation trends of these inhomogeneous stations during 1960-2009 are distinctly different from their nearby stations. Ratio method is applied to adjust inhomogeneous series and then the space homogeneity is improved, which suggests that the adjustment is efficient.

Key words: precipitation, homogeneity, SNHT, ratio adjustment method