Cellulase of the waste material from Lentinus edodes was prepared by ultrasonic extraction, the effects of ultrasonic power, ultrasonic time and liquid-solid ratio on the activity of cellulase were studied through single factor tests and response sur-face analysis.The results showed that the optimum process parameters were obtained as follows:ultrasonic power was 500 W, ul-trasonic time was 15 min, liquid ratio was 20∶1, three validation tests under these condition...