In order to understand the effect of the size on the quality characteristics of blueberry, blueberries were divided into large, medium, and small based on the weight. The comparison of physical-chemical properties, nutritional composition, antioxidant activity, juice produce ability and volatile compounds were analyzed. The results indicated that the effects of fruit size on varieties and indexes were different, the juice yield were decreased with the fruit size decreasing for all four cultivars. However, fruit size has little effect on fruit index, water content, sugar, TSS, and fruit juice color. The total phenol content of medium fruit was significantly lower than that of large fruit and small fruit. The volatile compounds of juice of Gardenblue is higher than the other three cultivars, and the fruit size has some influence on it without an obvious pattern. It can be seen, for cross-planting blueberry orchard, blueberry picking should be separated by the size to avoid different varieties.