Objective] This study was conducted to optimize cameI ia seed sheI fer-mentation conditions for ceI uIase production by Trichoderma koningi using response surface methodoIogy. [Method] Fermentation conditions for ceI uIase production from Trichoderma koningi were optimized with response surface method (RSM) by taking carboxymethyI ceI uIase (CMCase) activity as a response indicator. Three factors that affecting CMCase activity were screened out using singIe factor test among pretreatment methods of raw material, nitrogen sources, initial pH values, inocuIum voIume, fermentation time and voIume of Iiquid medium, they were fermentation time, initial pH value, and voIume of Iiquid medium. The optimum conditions of fer-mentation and interaction of the three factors were determined through Box-Behnken design and regression analysis using Design-Expert software. [Result] Pretreatment of cameI ia seed sheI with alkaline was most conducive to CMCase production. The use of 0.2% (NH4)2SO4 as nitrogen source, inocuIum size of 5%, initial pH value of 5.8 and voIume of Iiquid medium at 22 mI were the best fermentation conditions for maximizing CMCase production by T. koningi from cameI ia seed sheI . Under these conditions, 179.15 U/mI of CMCase was obtalned after 5 d of fermentation, which was improved by 24.52% compared with the maximum CMCase activity of singIe factor test. [Conclusion] The resuIts wiI provide some references for use of cameI ia seed sheI and ceI uIase production.