A procedure for the quantitative estimation of mono- (MG), diglycerides (DG) and propylene glycol mono fatty acid esters (MP) in margarine and shortening was studied. After the esters was cleaned up by thin layer chromatography, they were estimated individually by programmed temperature gas chromatography. In this procedure cholesterol was added to the sample as internal standard. Samples with known quantities of MG, DG or MP were analyzed, and recoveries of them were about 97-105%. Several commercial samples of margarine and shortening were analyzed by the proposed method, and results obtained as follows: MP was not detected in any sample, but MG and DG were detected in most samples, and quantities of them were different from one another; total quantities of them in margarine were from trace to 2.2mg/100mg, and those in shortening were from trace to 7.1mg/100mg.