Abstract: In this paper，rapeseed proteins were hydrolyzed by two different enzymes to prepare antihypertensive peptides. Alcalase and Neutral protease were selected to prepare antihypertensive peptides. Angiotensin-converting enzyme inhibitory activity (ACEIA) is analyzed by UV spectrophotometer. The effects of three crucial factors on the ACEIA of rapeseed proteins were analyzed by single-factor method, Subsequently, Box-Behnken experimental design combining with response surface methodology and quadratic programming was employed for maximizing the Alcalase-catalyzed hydrolysis of rapeseed proteins and a quadratic regression model was obtained using the Design-Expert software. the determination of optimum conditions of the rapeseed protein hydrolization was performed and the results listed as follows： substrate concentration 5.65 %, ratio of enzyme to substrate ([E]/ [S]) 6.5%，temperature 54.9 ℃, The theoretical value of ACEIA is 50.303%,and the actual value is 50.12%.