In this paper, the contents of ascorbic acid (AsA), glutathione (GSH), and related enzyme activities of Lgalactose dehydrogenase (GalDH), Lgalactono14lactone dehydrogenase (GalLDH), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR) and ascorbic acid peroxidase (APX) were investigated during the fruit development in sweet cherry ‘Satonishiki’. The results showed that: (1) the contents of total AsA, AsA, DHA and GSSG was the highest at the 0 day after anthesis (DAA), and then decreased persistently. However, the contents of total GSH and GSH was first increased and then decreased. (2) The accumulation of AsA and GSH increased during the whole growth process of sweet cherry fruit, especially during the second rapid growth period of fruit development. Different enzymes involved in metabolism of AsA showed different patterns during the development of sweet cherry fruit, but the changes of GalLDH, MDHAR and DHAR activities were similar to that of AsA. (3) The correlation analysis showed that they had a significantly positive correlation with the content of AsA, which indicated that they may be the key enzymes of AsA accumulation in sweet cherry fruit.