Abstract:In the paper, the seed oil of 46 woody species which belong to 19 fami- lies in southern Yunnan had been studied. Their physical-chemical nature- refractive index, specific gravity, saponification Yalue, acid value and iodine value were determined. Quantitative constitution of saturated and unsaturated fatty acid were analyzed.Among these 46 species, Horsfieldia pandurifolia H. H. Hu, Hors- fieldia tetratepala C. Y. Wu, Pterospermum menglungense Hsue, Loese- nerlella yunnanensis (Hu) Merr., Dracontomelon macrocarpum H. L. Li and Litsea dilleniaefolia Bai et P. H. Huang are endemic species to Xi- shuangbanna.