Osteoarthitis (OA) of the knee is a common disease in elderly and female patients. It always affects the patient's life through limited of motion or deformity of the joints that it causes. This study attempts to evaluate the effect of acupuncture therapy on the patient with OA of the knee. All the subjeats were acupuncture or rheumatology patients. They were all definitely diagnosed as having OA of the knee. Thirty patients received acupuncture therapy. Bilateral Yanglingquan (GB-34) were the main points used. Comparison of the difference before and alter acupuncture therapy was based on objective pain score and subjective knee flexion angle. All the data were analyzed using t-test statistic method. The results show: (1) pain was significantly relieved after acupuncture therapy according to the pain score (P＜0.01): (2) the knee flexion angle has significantly changed from 92.9° to 70.4° (P＜0.05); (3) effectiveness was shown in 80% of patients and significant improvement in 23%. According to the results of this study, the overall short-term effect of acupuncture therapy on knee OA is significant. Acupuncture can relieve the pain, increase the range of motion and improve the quality of daily life. Although acupuncture can be used as alterative therapy, the meahanism still needs further evaluation and study.