Abstract: In order to study the application of chemical interesterification in custard tart special oil, proportion of coconut oil, soybean oil, palm stearic and palm oil were blended in various ratios, according to physicochemical index.One group was selected as the model for custard tart oil base and then subjected to chemical interesterification reaction.The effect of the interesterification were detected by comparing slip melting point, melting property, triacylglycerol composition, crystal form, fatty acids and solid fat content.The results showed that slip melting point decreased from 41.5 to 39.1℃.The concentration of disaturated triacylglycerol greatly decreased by 29.7%.Alternatively, the triunsaturated, trisaturated and diunsaturated triacylglycerol increased by 32.9%, 32.1% and 47.5%, respectively.In addition, X-ray diffraction analysis revealed that interesterification increased the proportion of β'polymorph from 42.8% to 73.9%.Oleic acid and stearic acid contents were increased by 8.4 times and 7 times respectively, while lauric acid and arachidonic acid were decreased by 97.6% and 97%.Solid fat content at 25℃ decreased.The arteriosclerosis index after the reaction was lower than the reaction.Taken together, the interesterified fats showed desirable physical properties and suitable crystal form (β'polymorph) for possible usage as a spreadable custard tart stock.