Abstract: Homogeneous climate series is the basis especially for conducting and researching the characteristics of climate change.This paper has applied methods of standard normal test (SNHT),penalized maximal T test( PMT) and rank test (Mann-Kendall) study of annual precipitation homogeneity of Yunnan national level ground observing stations in the past fifty years.The result shows there are existing non-uniform sequences in annual precipitations.We have researched SNHT ratio correction and matching (QM) correction methods correct testing results and analyzed rainfall variation characteristics of Yunnan in the past 50 years and after correction in a preliminary analysis.It shows before and after adjustment,annual precipitation spatial distribution remain more or less the same,but there still exit differences in local area.After correction,the mutation trend has been eliminated and the variation trend and distribution of average annual rainfall have become more reasonable.