Abstract:[Objective] To evaluate the clinical efficacy and safety of Huamoyan granules in the treatment of knee osteoarthritis. [Meth-ods] A total of 467 patients with unilateral osteoarthritis were included in this study and randomly divided into two groups. Among them, 350 patients in the trial group were given Huamoyan granules orally 1 bag/time and 3 times/day, which contained 13 medicinal herbs including Prunella, Ligustrum, Herba leaf, Astragalus, tetrandrhexis, Coix seed, Tuckahoe, loofah, Zeilan, Salvia miltiorrhiza, Angelica sinensis, Achy- ranthes Herba Siegesbeckiae, while the 117 patients in the control group received the granule simulation agent orally 1 bag/time and 3 times/ day, which was similar with the Huamoyan granules in appearance, character and odor without any active ingredients. The treatment course was lasted for 24 weeks in both groups, and the clinical, ultrasonic and blood test data were compared between the two groups. [Results] The adverse reaction rate during the treatment was 2.0% in the trial group, while 2.6% in the control group, which was not statistically significant (P>0.05). The knee circumference, WOMAC score and VAS score for pain decreased significantly (P<0.05), while the comprehensive effec- tive rates were significantly increased in both groups over time (P<0.05). Although there were no significant differences in the abovesaid items between the two groups before treatment (P>0.05), the trial group proved significantly superior to the control group in terms of knee cir- cumference [(36.6±2.8) mm vs (37.4±2.9) mm, P<0.001], WOMAC score [(27.0±21.5) vs (46.5±28.9), P<0.001] and VAS score [(3.0±2.4) vs (4.9±2.9), P<0.001] and comprehensive efficiency (92.2% vs 60.4%, P<0.001) 12 weeks after treatment. During the follow-up period, the rate of symptom aggravation was 7.1% in the trial group, whereas 29.1% in the control group, which was statistically significant (P<0.05). Re- garding ultrasound, the trial group was significantly better than the control group in terms of depth of effusion in suprapatellar bursae [(4.0± 2.5) mm vs (4.9±2.7) mm, P<0.001] and suprapatellar synovial thickness [(1.6±1.7) mm vs (1.9±1.8) mm, P<0.001] 12 weeks after treatment. As results of blood test, the trial group also proved significantly superior to the control group in CTX-Ⅱ [(6.9±2.2) μg/L vs (8.2±4.0) μg/L, P=0.001] and IL-6 [(32.8±2.7) pg/ml vs (50.0±5.6) pg/ml, P<0.001] 12 weeks after treatment. [Conclusion] This Huamoyan granule does relive the joint swelling and pain of knee osteoarthritis, improve the motor dysfunction with less adverse reactions, while good safety.