【Objective】 To explore the therapeutic effect of autologous platelet-rich plasma (PRP) in the treatment of patellofemoral osteoarthritis (PFOA) based on the Magnetic Resonance Observation of Cartilage Repair Tissue 2.0 (MOCART 2.0) knee score system. 【Methods】 A total of 22 patients (28 knees) with PFOA treated by intraarticular PRP injection in our hospital from January 2020 to December 2023 were enrolled in the study. The nuclear magnetic resonance(NMR) images before and after treatment were compared using the MOCART 2.0 knee score system. Visual Analog Scales (VAS) score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score before and after treatment were evaluated and compared, and adverse reactions were observed during the treatment. 【Results】 The MOCART 2.0 knee score showed no difference before and after treatment (53.4±12.2 vs 49.9±2.1)(P>0.05). In the subgroup analysis, the "signal intensity of the repair tissue" score and the "subchondral changes" score were better than those before treatment as(5.5±1.5)vs(4.6±1.5)and(15.9±4.3)vs(13.2±6.4)(P<0.05). There were no significant changes in indicators as " degree of cartilage filling" , " integration with adjacent cartilage edges" , " repair of tissue surface structure" , " repair of tissue structure" and " bone changes" (P>0.05).The VAS score and WOMAC score gradually decreased at 1 month, 3 months and 6 months after treatment and were better than before treatment (P<0.05). Incidence of adverse reactions was 4% (4/112). 【Conclusion】 Intraarticular PRP injection is an effective and safe option for treatment of PFOA, and can improve the cartilage signal intensity and alleviating subchondral bone edema.