Abstract: In order to study the effect of sugar esters on their biological activities,the biological activity of glucose( galactose,lactose) stearic acid ester from two aspects of the antioxidant activity and the antibacterial activity were studied.In vitro antioxidation experiment showed that 200 μg / m L various compounds all had the ability to remove O-2·,·OH and DPPH·.And there was no significant difference in the antioxidant capacity of the compounds.The results of antibacterial experiment showed that 400 μg / m L glucose( galactose,lactose) stearic acid monoester can effectively inhibit the bacteria( Escherichia coli,Staphylococcus aureus,Bacillus subtilis and Salmonella bacillus coli) growth,but on the fungi( Rhizopus and Mucor,Penicillium and Aspergillus) had no obvious inhibitory effect.And there were no significant difference in the antibacterial activity of the compounds.