Pouteria campechiana, a fruit cultivated in many provinces of the Mekong Delta, is typically eaten fresh and has many benefits to human health. Therefore, quality control during storage of this fruit is very important for fresh consumption and food processing. This study was conducted to investigate the effects of postharvest maturity on the quality of the fruit stored at room temperature, mainly on its chemical composition and bioactive compounds content. The results showed that storage time greatly affected the amounts of carotenoids, tannin, phenolic and flavonoids: the highest content of carotenoids, polyphenols, flavonoids were obtained at day 10th of storage while tannin content gradually declined. The greatest antioxidant activity of fruit extracts was also obtained after 10 days storage. It was recommended that the highest nutritional value of Pouteria campechiana can be achieved from 8 to 10 days after harvest.