Abstract: Paeonia decomposita is potentially usable for developing oilseed peony，because of its large seed yield and obligate seed reproduction. We studied the 1 000-seed weight，kernel oil yield，composition and relative content of fatty acids in 7 wild populations，and measured their correlations with soil factors. The results showed that：Mean 1 000-seed weight was（311.65 ± 46.45）g；Mean kernel oil yield was 32.23% ± 1.96%，differences were significant among populations. Seven fatty acids were detected，including i.e. palmitic acid，heptadecanoic acid，stearic acid，oleic acid，linloeic acid，linolenic acid and cis-8-eicosenoic acid；Unsaturated fatty acids accounted for 91.94%–93.70%，the relative were different among populations. Soil available potassium content had significant negative correlation with oil yield；Both soil organic matter and total nitrogen content had negative correlation with linloeicacid content. There was no significant correlation between soil factors and other oil constituents.

Key words: Paeonia decomposita, wild population, peony seed oil, composition of fatty acids, unsaturated fatty acids