The fermentation of L-lysine by Corynebacterium glutamicum LS260 using cottonseed  protein hydrolysate instead of soybean meal hydrolysate was studied and the optimum additive  amount of cottonseed protein hydrolysate was determined by comparison of fermentation effects. The  results showed that when 0.3% and 0.8% of hydrolyzed cottonseed protein were added in the seeds  and fermentation medium respectively, the lysine production increased to 265 g/L, which increased  by 9.05% compared to the control, and the maximum sugar acid conversion rate reached 69%.