Objective:To evaluate the effects of oral PeptanTM collagen peptides for 6 months on knee joint pain and function in female patients with knee osteoarthritis(OA).Methods:a prospective,double-blind,randomized,placebo-controlled study was conducted at the 6th People's Hospital affiliated to.100 eligible female OA subjects selected through screening were included in the study and sighed informed consent.The subjects received either PeptanTM collagen peptides(CP) 8g (n=50) or placebo (n=50) daily for 6 months.Each subject was evaluated for knee joint pain and function by using the standard tools (WOMAC scores and Lysholm scores) and assessment the joint symptoms and physical finction at the baseline (month 0),and months 3 and 6.Results:The data from all subjects (n=95) were evaluated.WOMAC score and Lysholm score showed statistically significant difference with the CP group(n=48) compared with the placebo group(n=47)who treated for 6 months:CP group vs placebo group (WOMAC score 11.33±4.28 vs 15.00±3.45) and Lysholm score 85.24±8.88 vs 79.73±9.62) (P<0.001).However,no significant difference between two groups for 3 months was found (P>0.05).Moreover,the proportion of clinical effect was also found significant difference between the placebo group and the CP group.Conclusion:our study suggested that taking collagen peptides 8g/d for 6 months can improve knee joint pain and function in subjects with knee osteoarthritis.