To reduce content of free gossypol in cottonseed meal,this paper focused on the optimization of the condition of solid-state fermentation raw cottonseed meal with Enterococcus faecalis by response surface method.Firstly,the effects of independent variables(ratio of material to water,initial pH,fermentation time,inoculation amount and fermentation temperature) were evaluated by single factor analysis.The important factors affecting the content of free gossypol in fermentation cottonseed meal were ratio of material to water,initial pH and fermentation time.Secondly,the optimum fermentation conditions for free gossypol degradation were confirmed by Box-Behnken experimental design.The results showed that the optimum conditions were as follows: ratio of material to water was 1∶ 0.53,initial pH was 6.57,fermentation time was 3.06 days.Under the optimum condition,the content of free gossypol of fermentation cottonseed meal was 231.68mg/kg and the degradation rate of free gossypol was 67.85%.