Area weighting method was used to calculate average farmland natural quality in Lancang River basin in Yunnan Province,and statistical analysis techniques was used to analyze space distribution features of farmland natural quality inside the basin on the basis of farmland grading results of Yunnan Province. The results indicated that farmland natural quality zone scopes were divided into 1 - 26 grades,and every grade areas had great discrepancies,which showed a typical type skewness distribution and obvious space differences. Farmland natural quality zones presented a certain nonlinear correlation with soil type changes,latitude changes,and climate changes,etc. With the increase of latitude,decrease of climate heat and soil texture,the natural quality of farmland tends to decline. Discussing the space distribution features of farmland natural quality in Lancang River basin would optimize water allocation within the basin,provided scientific foundation for precisely mastering soil data,rationally utilize the land and formulate differentiated cultivated land quality promotion strategies.