【Objective】 To analyze the differences of botanical characters, berry quality, raisin polyphenols and antioxidant activity between Thompson Seedless and long-berry Thompson Seedless grape in the hope of providing new germplasm resources for grape breeding.【Methods】 V.vinefera cv.Thompson Seedless and bud mutation Long-berry Thompson Seedless were used as material, in the open field of the experimental vineyard,to investigate botanical character, photosynthetic response curve, berry quality and raisins quality and analyze the relationship between phenolic and antioxidant activity of raisins.【Results】 The results showed that, the main variation characteristics of bud mutation Long-berry Thompson Seedless were the color of young leaves, tender tips and petioles.Compared with ordinary Thompson Seedless, the color of young leaves was green with red bands, ventral new shoot color was green with red bands, dorsal internode color was green with red bands, and intersegmental ventral was green with red band.Germination rate of Thompson Seedless was higher than Long-berry Thompson Seedless, which were 65.00% and 63.82% respectively, germination rates of Long-berry Thompson Seedless were 50.48% and 53.45% respectively, in 2022, in 2023.The shape index of Long-berry Thompson Seedless were always higher than that of Thompson Seedless, the maximum shape index of Thompson Seedless and Long-berry Thompson Seedless were 1.80 and 2.12, after 16 d and 28 d after flowing, respectively.Berry quality, reduce sugar, sugar-acid ratio of Thompson Seedless were significantly higher than those of Long-berry Thompson Seedless, and there were no difference for bunch weight, bunch length, bunch width, soluble solid, titratable acid, Vitamin C, chromatic aberration.Drying rate, mean weight of Thompson Seedless were significantly higher than those of Long-berry Thompson Seedless, shape index of Long-berry Thompson Seedless was significantly higher than that of Thompson Seedless.Total flavanol, total flavonoids, total tannin, total phenol of Long-berry Thompson Seedless were significantly higher than those of Thompson Seedless, and their content were 1,808.59、2,286.43, 51.11, 98.53 mg/kg, respectively.DPPH and FRAP free radical scavenging capacity of Long-berry Thompson Seedless were significantly higher than Thompson Seedless, ABTS free radical scavenging capacity of Long-berry Thompson Seedless lower than Thompson Seedless, and no difference.The correlation coefficient were greater than 0.926 for total flavanol, total flavonoids, total tannin, total phenol, DPPH and FRAP free radical scavenging capacity, and their differences were significant or extremely significant.ABTS free radical scavenging capacity was negatively correlated with total flavanol, total flavonoids, total tannins, total phenols, DPPH and FRAP free radical scavenging capacity with litter difference.【Conclusion】 Bud mutation Long-berry Thompson Seedless can be used as an excellent variety and provide new germplasm resources for breeding.