Abstract: Objective To observe the effect of different time windows and interventions on skin pressure ulcers and ischemiareperfusion (I/R) injury in rats. Methods Sixty-eight SD rats were randomly divided into blank control group (n=4) and model group (n=64). The rats in the model group were randomly divided into group A (n=32) without intervention and group B (n= 32) with post-conditioning. The degree of skin compression, neutrophil infiltration and serum levels of free radicals were observed in the rats after compression for 2, 4, 6, and 8 h (8 rats at each time point). Results A significant difference was found in the severity of skin damage among the control group, group A, and group B (P=0.001), and the injury was milder in group B than in group A. Severe skin lesions occurred in 2 rats after skin compression for 6 h, as compared with 6 after compression for 8 h (P=0.043), but in none of the rats after compression for 2 or 4. Seventeen rats in group B and 15 in group A showed grade 1 neutrophil infiltration in the skin lesions, and 8 rats in group B and 10 in group A showed grade II neutrophil infiltration (P= 0.002). Neutrophil infiltration was the mildest in rats with a 2-h compression, and exacerbated progressively and significantly as the compression time extended (P=0.027). With the prolongation of the intervention time, the rats in both groups A and B showed decreased SOD and increased MDA and NO levels, and overall the I/R injury was milder in 2- and 4-h compression groups than in 6- and 8-h compression groups. The level of serum SOD was significantly higher and MDA and NO levels were significantly higher in group B than in group A (P<0.05). Conclusion Ischemic post-conditioning can relieve I/R injury in acute pressure ulcer in rats. The effective time window for intervention is within 6 h of ischemia, and the effect of ischemic postconditioning is optimal within 2 h. Ischemic post-conditioning can alleviate free radical injury and inflammation caused by I/R injury.