[en] The spontaneous sport mutant of Fujiminori was discovered in grape garden of Xiaying county at Ningbo city in 1993. The biological, botanical characteristics and fruit quality trait (such as total soluble solid, titratable acid, total water soluble sugar, reducing sugar, free Vc, organic acid and aroma etc.) of the mutant were continuously investigated from 1994 to 1999. The results showed that the sport mutant grew more vigorously, having multiple-bearing capacity in the year cycle. Fruit quality determination demonstrated that total soluble sugar, reducing sugar, soluble solids content and aroma contents of the mutant were higher than those of maternal plant in different degree, while titratable acid content of mutant was deceased. Meanwhile, it was also found that the berries of mutant are firmer and have longer storage life. The RAPD analysis of the genomic DNAs extracted from the young leaves of the spontaneous sport mutant indicated that there were some differential bands in the PCR amplified products using the arbitrary primers, which indicated the genotype diversity happened in the spontaneous mutation of grape.The mutant had been successfully developed the new grape variety named as 'Yongyou No. 1' via selection breeding method. The variety was approved by Ningbo Science and Technology Bureau in 1999 and was rapidly planted at other regions, such as Fenghua County, Yuyao County, Cixi County, Ninghai County, Shaoxing City, Jiaxing City and Hangzhou City, etc. Due to its high quality and productivity, it exhibits the extensive application potential in the future. (author)