Abstract: 【Objective】 To discuss the effects of selenium fertilizer concentration and application period on selenium content and comprehensive quality of grape berry in the hope of providing theoretical basis for the production of selenium-rich grapes and the rational application of selenium fertilizer. 【Methods】 Field experiments were carried out to study the effects of foliar spraying of nano-selenium fertilizer on the quality and selenium content of three cultivars of grapes, using Creessen Seedless (small grain), Creessen Seedless (large grain) and Shine Muscat as materials. 【Results】 The total selenium content of three grape berry increased with the increase of selenium application; At a certain concentration of selenium application, the total selenium content of the three grape berry sprayed with selenium fertilizer in the big and young fruit stage reached the maximum. Among them, Shine Muscat had better ability to absorb and enrich selenium at different selenium concentrations and application period than Creessen Seedless (small grain) and Creessen Seedless (large grain), and the highest selenium content was 0.176 mg/kg at the large and young fruit stage. Leaf selenium fertilizer could improve the fruit quality by affecting the contents of soluble solids, total acid, total sugar, and proanthocyanidins of three kinds of grapes, but it had no significant effect on the appearance index and the content of resveratrol glycosides. 【Conclusion】 It is recommended that the most suitable spraying period of the three grape varieties is the big and young fruit stage, and the best spraying concentration on leaves is 9.15 L/hm².