Abstract: Based on the resin flow measurement of Pinus yunnanensis trees growing on three localities, Lijiang, Kunming and Gejiu of Yunnan Province, it recovered that the resin flow exhibited significantly differences among the three localities. It was suggested that resin flow amounts were negatively related to the degree of latitude. In the same measuring locality, the resin flow was related to the slope orientation. Generally, the resin flow of the trees growing at the northern slope was smaller than that at the southern slope. No significances had been discovered for the resin flow among different orientations of the same tree. In general, the resin flow of the trunk increased with the trunk height. However, the present study did not measure the resin flow inside the crown of the tree.