The distribution of L-ascorbic acid AA and dehydroascorbic acid DHA in wounded and intact skin of guinea pig was investigated to elucidate the utilization of AA during tissue regeneration. Male guinea pigs fed an AA-free diet for 14 days were surgically injured on the dorsal skin, followed by intraperitoneal supplementation of AA (0.5, 5 and 50 mg/day/animal) for 4 days. The wounded skin, its surroundings and intact skin in each animal were removed for the determination of AA, DHA and collagen. The collagen content in wounded and intact skin increased in dose-dependent manner up to 5 mg AA/day, although neither the wounded nor the intact skin of the group supplemented with 50 mg AA had a higher content of collagen than those supplemented with 5 mg. In each group, the wounded skin had only about half the collagen of intact skin. AA content in the wounded skin of the groups supplemented with 5 and 50 mg AA were significantly lower than that in the other parts of their skin, whereas DHA content in wounded skin increased markedly. These results indicate that other factors besides collagen synthesis may enhance the oxidation of AA in the early stage of tissue regeneration.