Abstract: Objective To investigate the effect of intra-articular cavity injection of autologous plateletrich plasma on osteoarthritis of knee. Methods A prospective control study was conducted in 84 patients with osteoarthritis of the knee joint from July 2016 to July 2017 in the Hospital of Wuhan Sports University. According to the principle of random and equalization，the cases were divided into the study group（intra-articular cavity injection of autologous platelet-rich plasma）and the control group（intra-articular injection of sodium hyaluronate）. The joint function，pain condition and safety of two groups were compared on six months after operation. Results After treatment and at the end of treatment，both groups had higher Lysholm knee score than that before treatment，and WOMAC score was lower than that before treatment（P < 0. 05 ），and the study group was better than the control group（P < 0. 05 ）；after treatment and at the end of treatment，the pain score of both groups was lower than that before treatment（P < 0. 05），but the difference between the two groups was not statistically significant （P < 0. 05 ）；during the treatment，the difference of adverse reactions incidence of the two groups was not statistically significant（P > 0. 05 ）. Conclusion The therapeutic effect on knee osteoarthritis with intra-articular cavity injection of autologous platelet-rich plasma is more ideal，it can improve joint function，relieve pain，and has less adverse reactions，it is worthy of popularization and application.

Key words: osteoarthritis of knee joint, autologous platelet- rich plasma, sodium hyaluronate, articular cavity