"Xiaobai" apricot is one of the most popular fruits in China. However, during postharvest storage, fruit aroma loss occurs easily. In this study, factors affecting the aroma changes in different ripening stages of "Xiaobai" apricot during postharvest storage were searched. Immature and mature "Xiaobai" apricot samples were collected and monitored for sensory changes during postharvest storage. After 25 days of storage, the aromatic ester and alcohol abundance in mature showed a decrease, related to the loss of characteristic aroma. Immature fruit still tasted sour with an indistinct characteristic aroma, as a result of decreased alcohol and increased acid abundance. The ATT, ADH, PDC, and LOX genes were identified, and their expression levels were detected at different ripening stages during storage. The correlation analysis showed that the expression of LOX and ATT was positively correlated with the variation of aromatic ester (P<0.05), a key factor affecting the apricot aroma during postharvest storage.