Objective:To explore the effects of processing on the content and components on the fatty acid in Semen Raphani and decocting.Method:The content of the fatty acid in the product and decocting was determined by gravimetric method.The oil from Semen Raphani was esterified with carbinol and analyzed by GC-MS.Result:The major fatty acids in Semen Raphani were 13-(Z)-docosenoic acid,9-(Z)-octadecenoic acid,9,12-(Z,Z)-octad-ecadienoic acid,9,12,15-(Z,Z,Z)-octadecatrienoic acid,11-eicosenoic acid,hexadecanoic acid...