Polyethyleneglycol-adsorbed–superoxide dismutase (PEG-SOD), has been proposed as an effective agent for reducing free radical-mediated injury. The objective of this study was to investigate a protective effect of PEG-SOD supplementation on ovarian tissue during transplantation. Ovaries from F-1 mice were collected and vitrified. After warming, ovaries were autotransplanted under kidney capsule. Mice were randomly divided into four groups according to dose of PEG-SOD, (0 U/ml, 100 U/ml, 1,000 U/ml and 10,000 U/ml respectively). Grafted ovaries were retrieved 2, 7 and 21 days later. PEG-SOD was treated by intraperitoneal injection once every 48 hours and especially for 21 days group, after first week treatment, PEG-SOD was treated once every 4 days. Morphology of ovaries was assessed histological analysis and ELISA for FSH was performed to evaluate restoration of ovarian function. In 2 days groups, morphologically intact follicle ratio of 10,000 U/ml group was significantly higher than other groups. In 7 days groups, morphologically intact follicle ratio was significantly higher in all treatment groups. In 21 days groups, there was no significant difference of intact follicle ratio in total follicles in all groups but intact primordial, primary and secondary follicles ratio was higher in 10,000 U/ml group. FSH levels in blood serum were decrease as time goes on, but there is no statistical difference in each groups. In conclusion, the data of the present study show that PEG-SOD has a beneficial effect on preservation of the morphologically intact follicle.