To investigate the effect of miR-145 on the phenotypic modulation in rat corpus cavernosum smooth muscle cells. Corpus cavernosum smooth muscle cells were treated with either miR-145 mimics or miR-145 negative control. Cell proliferation were analyzed by the MTS assay and colony formation assay. Wound healing assay were performed to detect the effect of miR-145 on cell migration. The mRNA and protein levels of phenotype marker proteins were assessed by quantitative real-time polymerase chain reaction and western blotting. The intracavernosal pressure and mean arterial pressure were measured to assess erectile function at one month after the injection of platelet-derived growth factor-BB and miR-145. Our results showed that miR-145 inhibited the proliferation and migration of cavernosal smooth muscle cells. Smooth muscle cell phenotypic markers were also affected by overexpression of miR-145, as indicated by the increase in α-smooth muscle actin, calponin and smooth muscle myosin heavy chain expression. Moreover, significantly attenuated erectile function was observed in the platelet-derived growth factor-BB group as compared with the platelet-derived growth factor-BB+miR-145 group. These findings indicated that miR-145 regulate phenotypic modulation of corpus cavernosum smooth muscle cells.