Abstract: Objective To observe the therapeutic effect of etoricoxib on knee osteoarthritis（OA） and its safety. Methods Twenty-five patients with knee OA were treated with oral etoricoxib at the dose of 60mg/d.Its therapeutic effect and safety were assessed at weeks 0 and 3,such as Western Ontario McMaster Universities Osteoarthritis（WOMAC） index score（pain,stiffness,and daily activity difficulty）,score of knee pain and disease given by patients,and score of disease given by physicians.The treatment was judged effectively when the improved index was≥30%. Results All the indexes were significantly improved 3 weeks after treatment with etoricoxib（P＜0.01）.The therapeutic effect was≥68% except for stiffness and 80% for knee pain.Adverse reaction,mainly manifested as gastrointestinal symptoms and edema,occurred in 5 patients（20%）,which improved without reducing the dose or withdrawal of etoricoxib.No severe adverse events occurred. Conclusion Etoricoxib can improve the symptoms of knee OA with mild adverse reaction and good compliance.