Abstract: A field survey was conducted on the naturally distributed Pinus kesiya var. langbianensis communities in nine counties of southcentral and southwest Yunnan Province. The twoway indicators species analysis (TWINSPAN) was applied to quantitatively classify the communities, and the principal component analysis (PCA) and redundancy analysis (RDA) were adopted to coordinate the communities, with the relationships between the community type, species distribution, species diversity, and environmental factors analyzed. In the study area, the P. kesiya var. langbianensis communities could be classified into eight major communities. The dominant environmental factors affecting the communities and species distribution were in the order of altitude, mean annual air temperature, mean annual precipitation, and slope. The RDA ordination axes indicated that the distribution of the species, especially of the dominant species, varied with the variations of altitude, mean annual air temperature, mean annual precipitation, and slope. The distribution of P. kesiya var. langbianensis had significant negative correlations with altitude and mean annual precipitation, and significant positive correlations with mean annual temperature and slope. The generalized additive model (GAM) fitted the responses of species richness to various environmental factors, with the effects of altitude and mean annual precipitation on the species richness being significant (P<0.001).