Accumulation pattern of fatty acids during the seed development of peanut was studied with the cultivar 8130.Results showed that there were eight different fatty acids in the seed,they are oleic acid,linoleic acid,cetylic acid,stearic acid,docosanoic acid,arachic acid,tetracosanic acid,arachidonic acid.During seed development,the content of oleic acid increased gradually and the contents of other fatty acid decreased by degrees;Linoleic acid and oleic acid accounted for over 80% of the total fatty acids in mature seeds.The quantity of the total fatty acids increased rapidly during early stage of seed development,and increased slowly at middle stage,then increased rapidly in the seed maturity stage.The rate of oleic/linoleic(O/L)increasing gradually during seed development and achieved maximum in mature seed.