Abstract: Objective To measure food energy density directly by auto-calorie eter and evaluate the results.Methods One gram sample and the benzoic acid standard were put in cmcible,and lOm Iwaterwas added in the oxygen bomb of the auto-calorimeter After burning the sample under heunetic and sufficient oxygen condition the resultwas displayed Under strict quality control,the energy density of 48 samples including 8 kinds of infant food were detected.Results There was no significant difference bettween the two sets of the results(16.83-21.34MJ/kg and 16.10-19.4MJ/kg).All samples detected were of good quality in energy density.Conclusion Auto-calorieeter application in food energy measurement is a high automatic,simple procedure with excellent accuracy and sensitivity.