This study examined the relationships between emotion regulation behavior (ERB) and athletic injury psychological acceptance (AIPA) process which consists of psychosocial recovery factor (PSRF) and AIPA, from the viewpoint of enacted social support (SS). Athletes (N = 180) that had experienced an injury were divided into high-and low-SS groups based on SS scale. Next, a model, in which ERB variables have an influence on AIPA process, was examined using multiple-group structural equation modelling. The model indicated differences in the degree of SS. It was suggested that in the high-SS group, ERB of emotional expression and positive reappraisal were functional, and these ERB were positively mediated by PSRF of emotional stability and temporal perspective, respectively, which promoted AIPA. Whereas, it was suggested that ERB of emotional suppression and positive reappraisal were functional, and these ERB were positively mediated by temporal perspective, which promoted AIPA in the low-SS group. However, emotional suppression was also negatively mediated by emotional stability, which obstructed AIPA. These results are suggested that differences in athletes' support environment should be considered when designing interventions.