Aim To observe clinical effect and explore preliminary mechanism of Oleanolic acid strengthening atorvastatin lipid-lowering in patients with hyperlipidemia. Methods 107 cases of patients with hyperlipidemia were divided into atorvastatin therapy group or combination therapy group of atorvastatin and oleanolic acid, and the course of therapy was 3 months. The concentration of serum TC, LDLC , TG, HDLC were detected before and after treatment. The changes in serum lipid levels before and after treatment were compared between the two groups. Serum PCSK9 concentrations were detected by ELISA before and after treatment. Results General data including TC, LDLC, TG, HDLC were matched between atorvastatin therapy group and combination therapy group of atorvastatin and oleanolic acid. There were no significant difference in all compared data between two groups. All of two therapy protocols achieved remarkable results. Compared with the same group before treatment, TC and LDLC and TG were significantly decreased after treatment in two groups, and the difference was statistically significant （P<0.05） Compared with atorvastatin therapy group, TC and LDLC decreased more obviously in combination therapy group of atorvastatin and oleanolic acid, the difference was statistically significant （P<0.05）. The initial serum PCSK9 concentration difference was not statistically significant （72.4 ± 4.2 μg/L vs 71.1 ± 3.9 μg/L, P>0.05） in two groups. After treatment, in atorvastatin therapy group, serum PCSK9 concentration increased by about 30%, the difference was significant （72.4 ± 4.2 μg/L vs 95.1 ± 3.7 μg/L, P<0.01） compared with before treatment in combination therapy group, atorvastatin and oleanolic acid serum PCSK9 concentrations was slightly higher （71.1 μg/L± 3.9 vs 77.6 ± 4.4 μg/L） compared with before treatment, the difference was non-significant But in atorvastatin therapy group serum PCSK9 concentrations were significantly higher than combination therapy group with atorvastatin and oleanolic acid, the difference was significant （95.1 ± 3.7 μg/L vs 77.6 ± 4.4 μg/L, P<0.05）. Spearman correlation analysis was performed among the patients’ plasma total cholesterol, HDL cholesterol,TG, and LDL cholesterol and their circulating PCSK9 concentrations. PCSK9 correlated positively and significantly with both total cholesterol （r0.76, P0.001） and LDL cholesterol （r 0.72, P0.001）, but not with HDL cholesterol or TG （data not shown）. Conclusion Oleanolic acid can enhance atorvastatin lipid-lowering effect in hyperlipidemic patients, which may relate to oleanolic acid inhibiting PCSK9 expression.