Abstract: Objective:To study the effect of tea seed saponin on regulating blood lipid in hyperlipidemia rats.Methods:Sixty male Wistar rats were randomly divided into 10 normal groups(group C)and 50 model groups after one week of adaptive feeding.Group C was fed with basic diet and the model was fed with high fat diet.After successful modeling,the model rats were randomly divided into model control group(group H),positive control group(group P),tea seed saponin high,medium and low dose groups(group TSH,group TSM,group TSL),and were intragastrically administered. After 4 weeks of intervention,the lipid metabolism,liver function,and antioxidant capacity were measured. The AI index and liver index were calculated,and the degree of steatosis was observed by pathological section.Results:Compared with group C,the body weight,liver index,AI index,serum TC,MDA,AST and ALT were significantly increased(P<0.01),and serum TG and LDL-C were significantly increased(P<0.05),the serum HDL-C,SOD was significantly reduced(P<0.01),the liver showed obvious fatty degeneration characteristics.Compared with group H,in TSH group,the body weight,liver index,AI index,serum TC,TG were significantly lower(P<0.01),HDL-C was significantly increased(P<0.01),and ALT and AST were significantly decreased(P<0.01). <0.05),the degree of hepatic steatosis was significantly improved,SOD was significantly increased(P<0.05),MDA was significantly decreased(P<0.01).In TSM group,the body weight and serum TG were significantly decreased(P<0.05),liver index,serum TC,AI index,MDA decreased significantly(P<0.01),HDL-C and SOD increased significantly(P<0.05),and the degree of hepatic steatosis improved. There was no significant difference in the body weight,liver index and MDA in TSL group. Serum TC was significantly decreased(P<0.01),TG and AI index were significantly decreased(P<0.05),HDL-C and SOD were significantly increased(P<0.05),and the degree of hepatic steatosis was improved.Conclusion:Tea seed saponin can regulate the blood lipid level and liver function of rats with hyperlipidemia and improve its antioxidant capacity,which also consolidates the theoretical basis for its application in lipid-lowering medicine and health food.