Abstract: In order to get the optimum process parameters that inactivate the enzymes activities in blueberry juice during ultra-high pressure treatment,activities of peroxidase( POD) and polyphenol oxidase( PPO) were taken as the response values.According to the principle of Central-Composite experiment design,the mathematical model of enzyme residual activities and pressure,time and temperature were established.Design-Expert 8.0.6 was used for response surface analysis.The results showed that the optimum conditions for inactivating POD were: pressure500 MPa,time 5 min and temperature 40 ℃,after processing using these conditions,the residual activities of POD was 49.13%,the optimum conditions for inactivating PPO were: pressure 500 MPa,time 15 min and temperature10 ℃,under these conditions,the residual activities of PPO was 4.776%. Additionally,blueberry juice was treated under the conditions of pressure 500 MPa,time 15 min,and temperature 10 ℃,the passivation effect of POD and PPO was optimum.