Objective To observe the effect of platelet rich plasma (PRP)combined with core decompression on the steroid?induced avascular necrosis of the femoral head (SANFH) and on MMP/ TIM in rabbits. Methods < /b> A total of 42 New Zealand white rabbits were used in this study, and were randomly divided into 3 groups (decompression, combination and control groups, each n =14). The rabbit model of SANFH was established by i. m. injecting prednisolone acetate in the decompression group and combination group. The improved Landesberg method was used to make the platelet rich plasma. The decompression group received core decompression treatment while the combination group received PRP combined with core decompression for bone repair. X?ray photography of the hip joint of the two groups were taken at 2, 6 and 10 weeks after the surgery, and the Lane?Sandhu X?ray scores and new bone area ratio were compared. Venous blood samples of the 3 groups were collected and the bilateral femoral heads were taken for further examination. The left femoral heads were used for histopathological observation and the right ones were used to determine the expression of the mRNA of MMP?2,MMP?9, TIMP?1, and TIMP?2. Results The levels of MMP?2 and MMP?9 in the decompression group were higher than that in the combination group and control group after surgery. The levels of TIMP?1 and TIMP?2 in the decompression group were significantly lower than the combination group and control group (P < 0.05). The IL?6 level and the rate of empty bone lacunae in the decompression group were significantly higher than the combination group and control group (P < 0.05), and that of the combination group was higher than the control group (P < 0. 05). The combination group had a better joint imaging and histopathological evaluation than the decompression group after surgery. Conclusions Our findings demonstrate that PRP combined with core decompression can exert a positive effect on the MMP/ TIMP and bone tissue repair in the treatment of steroid?induced avascular necrosis of the femoral head in rabbits.