Abstract: Based on forest management inventory data in Kunming, spatial autocorrelation and spatial heterogeneity were used to analyze the spatial distribution of aboveground biomass of Pinus yunnanensis forests. The results showed that aboveground biomass density of P. yunnanensis forests had significant positive spatial autocorrelation and its intensity of spatial cluster was affected by the distance scale, especially in 51.6 km, where the spatial processes of clustering are most pronounced; the spatial distribution of aboveground biomass density of P. yunnanensis forests in Kunming was regular, the large high-high spatial clusters were observed in the northwest part and the low-low spatial clusters were observed in the northeast, central, southwest and southeast Kunming. The spatial heterogeneity of P. yunnanensis forests is mainly composed of random components and the results were affected by step size; the aboveground biomass density of P. yunnanensis forests is anisotropic, and the spatial variability varies with direction. The research scale of spatial effect for the aboveground biomass density of P. yunnanensis forests in Kunming is 51.6 km and 9 km, respectively. This study can provide reference for forest protection and management in Kunming.