The effects of pressure and temperature on the activity and the stability of Rhizopus chinensis lipase during high hydrostatic pressure treatment were studied. Based on the two-state model, the thermal denaturation of the enzyme was investigated and the isokineticity diagram was obtained. Within 0.1～200.0 MPa the enzyme activity increased with the pressure and the maximum activity was achieved at 200 MPa, which was 116% of that at atmospheric pressure. The activity began to decrease at pressure above 200 MPa and this tendency accelerated upon the pressure superior to 400 MPa. The high pressure treatment did not modify the optimal temperature of the enzyme. The enzyme exhibited the highest stability when it was treated at 200 MPa and 40 ℃. Its stability declined obviously when it was treated under pressure above 350 MPa. The above behavior could be explained by the isokineticity diagram.