Sterol compositions of three solanaceous plant seed oils i.e., tobacco(Nicotiana tabacum L.), datum (Datura stramonium L.) and Chinese lycium (Lycium chinerise Mill.) were analyzed by thin layer chromatography, gas liquid chromatography and gas liquid chromatography-mass spectrometry. Cholesterol, cholest-7-enol, campesterol, 24-methylenecholesterol, stigmasterol, sitosterol, and 28-isofucosterot were identified in 4-des-methylsterol fraction. 31-Norlanost-8-enol, 4α-methylcholest-8-enol, lophenol, 31-norlanosterol, obtusifoliol, 31-norcycloartenol, cyloeucalenol, gramisterol (24-methylenelophenol), and citrostadienol in 4-monomethylsterol fraction, and lanost-8-enol, cycloartanol, lanosterol, β-amyrin, 24-methylenelanost-8-enol, cycloartenol, lupeol and 24-methylenecycloartanol in 4,4-dimethylsterol fraction were identified respectively.