By pot experiment and foliar spray, the effects of different concentrations of sodium selenite（Na₂SeO₃） on ascorbate（AsA） content and related metabolic enzymes in "Sweet Charlie" strawberry fruits were studied. The results showed that exogenous Na₂SeO₃ could significantly improve AsA content in fruit, and decrease dehydroascorbate（DHA） content. Meanwhile, Na₂SeO₃ improve the activities of ascorbic acid peroxidase（APX）, ascorbic acid oxidase（AAO）, glutathione reductase（GR）, L-galactosate-1, 4-lactone dehydrogenase（GalLDH）, monodehydroascorbate reductase（MDHAR）, dehydroascorbate reductase（DHAR） in the fruit of strawberry. Among different concentrations of Na₂SeO₃, 30 mg/L Na₂SeO₃ show the best effects, whichcan be applied in strawberry production to improve ASA content in fruits.