To optimize enzyme hydrolyzing conditions for pin nut protein by pepsin，and test free radical scavenging effect of hydrolyzed protein． ［Method］By using pepsin to hydrolyze the pine nut protein in order to improve the hydrolysis process． At the same time，
the hydrolysates’effect on hydroxyl radical scavenging and reducing power were detected． The mass concentration of the soluble protein was
used as the response to conduct single factor experiment and orthogonal experiment． ［Result］The optimum conditions of the pine nuts protein
hydrolyzed by pepsin were as follows: enzyme concentration 7． 5 U per gram of substration，hydrolyzing temperature 50 ℃，hydrolyzing time
3． 75 h，pH 2． 0． The influencing factors’order pH ＞ hydrolysis time ＞ adding amount of pepsin ＞ temperature． The antioxidant experiments
showed that the enzymatic hydrolysis of the pine nut protein hydrolyzed by pepsin has the capacity of radical scavenging and reducing power．
［Conclusion］The study can provide reference basis for utilization and development of pine nut in depth．