The influences of supercritical CO2 on the total protein and alkali-soluble protein of E.coli was studied by SDS-PAGE analysis and the inactivation curve of E.coli by supercritical CO2.The results showed that the solubility of E.coli alkali-soluble protein(pH8.0) was significantly decreased by supercritical CO2 when E.coli was be inactivated by supercritical CO2.But there was no change of the species and content of total protein of E.coli was oberved.The survival rate of E.coli was 2.8%,and the content of soluble protein was decreased after 30min treatment at 37 ℃ and 10MPa,the survival rate of E.coli and the content of soluble protein was not more decreased when the pressure was increased up to 50MPa.