To explore the UV-B ultraviolet irradiation treatment on the major fruit quality and related enzyme activities in different developmental stages of blueberry,we chose Northland as plant material.The radiation time was 5 min,10 min and 15 min,respectively,and taking no irradiation as control.The result shows that:(1)with UV-B treated young fruit of blueberries,the soluble sugar content significantly increased 47% compared with control by 5 min treatment.The PAL activity increased the most significantly by 10 min treatment.The total phenols and anthocyanin accumulation increased 36% and 31% comparing with the control by 15 min treatment,but flavonoid content and CHI activity reduced significantly.(2)With UV-B treatment ginkgo blueberry,the flavonoids and CHI activity increased significantly by 5 min treatment.The soluble sugar and total phenolic contents increased 25% and 18% than the control by 10 min treatment.The anthocyanin and PAL activity increased the most significantly by 15 min treatment reaching at 48% and 151% comparing with the control.(3)With UV-B treated verarison blueberries 10 min,the soluble sugar and flavonoid contents decreased and the other material content increased significantly.(4)UV-B treatment did not change the regularization during the fruit development of the contents of soluble sugar,total phenols,flavonoids,anthocyanins,and PAL,CHI.(5)The activity of PAL was positively correlated to soluble sugar,total phenolic and flavonoid accumulation.But the activity of CHI was only positively correlated to soluble sugar.Research shows UV-B treatment made soluble sugar content increase at low dose and decrease at high dose.UV-B irradiation could promote the accumulation of total phenols,anthocyanin and flavonoids during ginkgo blueberries,decrease the CHI activity in young fruit,increase the PAL and CHI activities in ginkgo and verarison fruit,also could make positive influence about the major quality of blueberry.