High quality data series are not only the base of our study on climate change,but also the base of the diagnosing,forecasting and valuating climate.Because of sites moving and observation method changing,the climate data have been inhomogeneity for a long time.The original data applied in this paper sourced from Beijing meteorological information center,and were homogenized by the method of MASH(Multiple Analysis of Series for Homogenization).The MASH package consists of an interative procedure designed to ...