Abstract: The preparation of triglycerides rich in palmitic acid at sn-2 position was conducted through chemical interesterification in the present study,while palm stearin was used as the raw material and sodium methoxide as catalyst.The content and distribution of fatty acids in the raw material palm stearin were measured and analyzed first.And then the horizontal ranges of reaction time,sodium methoxide load and reaction temperature were determined by single factor experiments,which were further optimized by Box-Behnken center combination experiments.The results showed that the three factors all had significant effect on the content of palmitic acid at sn-2 position,and the order of the impact was reaction time>reaction temperature>sodium methoxide load.The optimal reaction conditions were as follows:reaction time 33 min,sodium methoxide load 0.33% and the reaction temperature 83℃.Under the above parameters,the sn-2 palmitic acid content of the obtained triglycerides could reach to 60.17%,which was increased by 21.37 percent point compared with the raw palm stearin.The afforded triglycerides rich in palmitic acid at sn-2 position could be used as ideal raw material for the preparation of substitute of human milk fat.