Objective:To study the therapeutic effects and security of combination of simvastatin with berberine on the patients with hyperlipemia. Methods:In clinical trial,a total of 99 patients with hyperlipidemia in our hospital were divided into 3 groups. Group A:SIMVA,Group B:BBR,Group C:combination of BBR with SIMVA. After 8 weeks of treatment,the Blood lipid,liver and kidney functions in the three groups were detected and compared. Rats fed the HFHC diet were randomly divided into 5 groups. They were the HFHC diet control group treated with saline (n=6),SIMVA at 6 mg/(kg·d)(n=9),BBR at 90 mg/(kg·d)(n=9),BBR (90 mg/[kg·d]) plus SIMVA(6 mg/[kg·d])(n=10),and SIMVA at 12 mg/(kg·d)(n=9),respectively for 30 days. Serum LDL-C,total cholesterol (TC),triglyceride (TG) and LDLR mRNA levels were assayed. Results:After 8 weeks of treatment,in the group of the patients with hyperlipemia,combination of BBR with SIMVA was more effective than the SIMVA or BBR monotherapy,markedly effective cases in the former group were 1-fold higher than that of SIMVA alone. The total effective rate of group C was 100%. Serum TC,TG were significantly different before and after simvastatin treatment(P < 0.01). Combination therapy reduced serum TC,TG and LDL-C,the levels of them were all significantly lower than these after simvastatin single-used in the hyperlipemia patients(P < 0.01). Comparing the three groups,in decreasing TC,TG,LDL-C,group C was more effective than group A (P < 0.01). Animal experiments piont out that the therapeutic effects of combination of half-simvastatin with berberine is correspond to entire amounts of simvastatin. We had not found any adverse effects in group C. Coadministration of berberine with simvastatin up-regulated LDLR mRNA to a level significantly higher than that of the monotherapies (P < 0.001). Conclusion:As compared with monotherapies,the combination shows an improved lipid-lowering effect with reduction of serum LDL cholesterol. Adding BBR to simvastatin could reduce the dose of simvastatin by at least 50%.The combination therapy display a new and effective regimen for hyperlipemia.