Abstract: Based on single-enzyme screening and single-factor tests analysis,the preparation conditions of ACE inhibitory peptides from Brazil nut protein were studied with response surface analysis methodology. The effects of four factors,including the time of enzymatic hydrolysis,the temperature,initial p H and substrate concentration,were mainly discussed on the enzymatic hydrolysis. Using the ACE inhibitory rate as responses,the optimum conditions of alcalase enzymatic hydrolysis were determined as enzymatic hydrolysis time 114 min,enzymatic hydrolysis temperature 57 ℃,initial p H10,3.24% concentration of the substrate,dosage of enzyme2000 U/g,and then the inhibition ratio of ACEIP was 69.83%. The results of the research were the basis for the efficient utilization of the Brazil nut protein.