To evaluate the clinical effect of Bushen Jianpi prescription in the treatment of severe osteoarthritis of the knee (KOA). Method:Sixty patients with severe KOA were randomly divided into treatment group and control group, with 32 cases in treatment group and 28 cases in control group. The control group was given health education, functional exercise, loxoprofen sodium tablets and glucosamine hydrochloride capsules orally, while the treatment group was orally given Bushen Jianpi prescription. The treatment lasted 2 weeks. The WOMAC scale and ISOA scale were used to score the disease before and after treatment, and the effect was evaluated according to the decline proportion of the score. Results:According to the WOMAC rating, the total effective rate was 78.13% in the treatment group, and that of the control group was 53.57%. According to the ISOA scale, the efficiency of the two groups was 81.25% and 78.57% respectively. The scores of symptoms and signs, maximum walking distance and the daily life were significantly decreased after treatment(P<0.01). After treatment, the maximum walking distance score in the treatment group was superior to that of the control group(P<0.05). Conclusion:Bushen Jianpi prescription can effectively improve the severe KOA symptoms.