OBJECTIVE： To observe clinical efficacy and safety of intraarticular injection of betamethasone and hyaluronate in the treatment of elderly knee osteoarthritis. METHODS： A total of 76 elderly patients with knee osteoarthritis were selected from our hospital during Jul. 2012 to Jul. 2015， and then divided into control group and observation group according to random number table， with 38 cases in each group. Control group was given intraarticular injection of Sodium hyaluronate injection 2 mL， once a week， for consecutive 3 weeks. Observation group was given Compound betamethasone injection 1 mL in the first week， and given sodium hyaluronate 2 mL， every week， in the following 2 weeks. Clinical efficacies and the occurrence of ADR as well as VAS score， WOMAC score， GQOLI-74 score and MMP levels before and after treatment were compared between 2 groups. RESULTS： Total response rate of observation group was 92.11％， which was significantly higher than 73.68％ of control group， with statistical significance （P＜0.05）. Before treatment， there was no statistical significance in VAS score， WOMAC score， GQOLI-74 score， MMP-1 level or MMP-3 level between 2 groups （P＞0.05）. After treatment， VAS， joint stiffness， joint pain and daily activity restriction score as well as MMP-1， MMP-3 were decreased significantly in 2 groups， compared to before treatment； physical pain， physiological function， physiological limitations， vitality， social function， emotional function， mental health and GQOLI-74 total score were increased significantly， and the each index of observation group was significantly better than that of control group， with statistical significance （P＜0.05）. No obvious ADR was found in 2 groups during treatment. CONCLUSIONS： The intraarticular injection of betamethasone and sodium hyaluronate in the treatment of elderly knee osteoarthritis can effectively reduce pain degree， improve knee function and quality of life， have good therapeutic efficacy and safety， the mechanism of which may be associated with the reduction of MMP level.