Abstract: ‘Kaisuan 1’is an excellent new cultivar bred by purification,rejuvenation and multi-generation back crossing,with local tomato cultivars in Guizhou as the basic materials. It is an indeterminate and semi-vining tomato with early-medium maturity,showing strong fruit-setting ability. The fruits are red and round,without green shoulders when immature,with high uniformity of fruit size and consistent ripening of fruit clusters,and the average single fruit weight is 6-10 g. Vitamin C 0.3036 mg · g^-1,lycopene 0.08651 mg · g^-1,soluble sugar 47.8 mg · g^-1,titratable acid 7.1 mg · g^-1,and soluble solids 8.20%. It exhibits moderate resistance to cucumber mosaic virus（CMV）,tobacco mosaic virus（TMV）,Fusarium wilt and root-knot nematode disease. The average yield reaches 30 598.8 kg · hm^-2,which is suitable for open-field cultivation in spring and protected cultivation in autumn in Guizhou,Guangxi,Hunan,Sichuan and other regions.

Key words: tomato, sour soup, cultivar