A method is developed for the determination of fatty acids in oils by capillary gas chromatography. The analysis conditions are optimized. A SE-30capillary column(25m×0.22mm×0.2μm) is used with the column temperature at 190℃, the flow rate of carrier gas at 1mL/min, and the split ratio of 1∶100. The contents of fatty acids in cotton seed oil, peanut oil, soybean oil, millet oil and lard oil are determined. The results show that the content of unsaturated fatty acids is normally higher than that of the saturated fatty acids. In tested oils, the content of linoleic acid in soybean oil is the highest, up to 60.02%.The content of unsaturated fatty acids in vegetable oil is higher than that in lard oil,while in millet oils up to 84.33%,and in lard up to 50.43%.