Abstract: In this paper,broccoli stems and leaves were used as raw materials,and proteins were extracted by boiling. The crude protein extracts were prepared by enzymatic hydrolysis to obtain the broccoli peptide extracts,which was then separated and purified by Valflow50 ultrafiltration and Sephadex G-15. The blood lipid-lowering function was screened by cell experiments. Finally,the blood lipid-lowering function was evaluated by animal experiments. The results showed that the protein contents of broccoli protein crude extracts was 49.6%. Enzymatic hydrolysis could enhance the hypolipidemic activity of broccoli protein,and the isolated component G15-Ⅱ had the strongest antihyperlipidemic function in vitro. The levels of TC and TG in blood of rats treated with 400 and 200 mg/kg were decreased(P<0.01),and the levels of HDL-C in 400 mg/kg group were increased(P<0.05),which indicated G15-Ⅱ had a blood lipid lowering effect. This study would provide basic data and scientific references for the in-depth development and comprehensive utilization of broccoli.