In order to study the anti-hyperlipidemic effects of Evening primrose, the changes of body weight, serum total cholesterol, serum HDL-cholesterol, serum triglyceride, serum LDL-cholesterol, serum total lipid and organ weight were observed after the liquid extracts of Single-dosage Evening primrose and Double-dosage Evening primrose were administered p.o to the hypercholestemic and hypertriglyceremic rats induced by 1% cholesterol diet during 10, 20, 30 days. The result were summarized as follows ; 1. The contents of body weight compared with control group was significantly decreased in single-dosage Evening primrose group during 10, 30 days and in double-dosage Evening primrose group did not show significant value. 2. The contents of serum total cholesterol with control group tend to be decreased in single-dosage Evening primrose group, but did not show significant value. Double-dosage Evening primrose group showed significant value during 20, 30 days. 3. The contents of serum HDL-cholesterol compared with control group was significantly increased in single-dosage Evening primrose group during 10, 20, 30 days. Double-dosage Evening primrose group showed significantly value during 30 days. 4. The contents of serum triglyceride compared with control group was significantly decreased in single-dosage Evening primrose group during 10, 30 days. Double-dosage Evening primrose group showed significant value during 20 days. 5. The contents of serum LDL-cholesterol compared with control group was significantly decreased in single-dosage Evening primrose group during 10 days. Double-dosage Evening primrose group showed significant value during 10, 20, 30 days. 6. The contents of serum total lipid compared with control group was significantly decreased in single-dosage Evening primrose group during 20 days. Double-dosage Evening primrose group showed significant value during 20, 30 days. 7. The contents of liver weight compared with control group was significantly decreased in single-dosage Evening primrose group and double-dosage Evening primrose group. The contents of kidney weight compared with control group was significantly decreased in single-dosage Evening primrose group. The contents of spleen weight compared with control group was significantly decreased in single-dosage Evening primrose group and double-dosage Evening primrose group. The contents of testis weight compared with control group tend to decreased in single-dosage Evening primrose group and double-dosage Evening primrose group, put did not show a significant value. From the above results, it was thought that Evening primrose could be applied effectively to the Hyperlipidemia.