To investigate the effects of pprI gene from Deinococcus radiodurans transferred by ,in vivo, electroporation on γ-ray injury of mice, the morphological changes of testis in the mice were observed. The pCMV-HA-pprI plasmid containing pprI gene was injected into the muscle of mice. The pprI gene was transfected into the cells by ,in vivo, gene electroporation technology. Then the control group and the transferred pCMV-HA- pprI group were exposed to γ-ray radiation of 6 Gy. The muscle tissue at the site of the injection and the testis tissue were taken on days 1, 7, 14, 28 and 35 after radiation. Then total protein was extracted and used to test the expression of PprI with western blotting technology. The testis specimen prepared by haematoxylin-eosin staining was then examined by light microscopy. The expression of PprI is remarkable on the 1st day after irradiation to prove that the pprI gene was successfully transfected into the mice. On the 1st day after irradiation there was no obvious pathological change of the testis tissue of the control group. On the 7th day there was degeneration and necrosis of some spermatogonia and spermatocytes in sections of tubules. On the 14th day, the reduction of spermatogonia was generally marked, and there was considerable reduction in the number of primary spermatocytes associated with atrophy of the seminiferous tubules. On the 28th day there was complete depletion of spermatogenic epithelium when spermatocytes and spermatids had largely disappeared, with no regeneration of spermatogonia and only sertoli cells nuclei remaining along the basement membrane. On the 35th day, spermatogonia were actively regenerating in some of the tubules. Compared with the control group, there was also no significant difference on the 1st after irradiation in the transgenic animal. On the 7th day the degeneration and necrosis of some spermatogonia and spermatocytes in sections of tubules was less than that of the control group. On the 14th day the reduction of spermatogonia was generally marked, and the number of spermatogenic cells reduced. By the 28th day some spermatogonia were actively regenerating in some of the tubules. By the 35th day the regenration of spermatogonia increased and began to stratify. The expression of the pprI gene transfected by ,in vivo, electroporation in mice irradiated by γ-ray shows an significant anti-radiation effect, and can promote the reparative process of testis injury from the mice.