Abstract: Placket-Burman (PB) design was applied to discover the most significant parameters affecting cellulase production by Trichoderma reesei RUT C30 on deglucosed starch obtained from yeast fermentation, and the condition of cellulase production was optimized by response surface method(RSM). Results showed that mass concentration of hydrolysate from hydrolysis of deglucosed starch and mass concentration of CaO were the two most significant parameters. The model between enzyme activity and these two parameters was build through the path of steepest ascent and RSM. Under optimized conditions, the levels of these two parameters were respectively 28.85 and 0.67g/L. The theoretical enzyme activity from 120h fermentation was 7.52FPIU/mL, and the maximal value was 11.16FPIU/mL from 156h fermentation. The maximal glucosidase activity reached 0.79IU/mL.