Grewia coriacea Mast. (Malvaceae) is fruiting tree of the Congolese spontaneous flora used in traditional pharmacopee to cure several pathologies. Its fruits are clustered and very appreciated by local populations for the jus their produce. They are green when unripe and become blackish red at the gustatory maturity. Given this change of color we aimed at assessing the total polyphenols and flavonoid content in the epicarp, the mesocarp and nuts of the fruits at various stages from physiological maturity, maturiy, early gustatory and gustatory maturity from dosage on the spectrophotometer. Based on the importance of phenolic compounds in treatments of several pathologies, this approach would provide an indication to consumers and trade-therapists using the fruits. Results showed the richness of the phenolic compounds in the fruits of G. coriacea which are more stocked at the gustatory maturity nevertheless the fruit period or the maturity stage considered. The aqueous solution better extracts total polyphenols with 11.47 mg EAG/g MS followed by the hydroethanolic extract with 9.1 mg EAG/g MS. Similarly, the aqueous and hydroethanolic solutions extract very well the total flavonoids with 21.46 mg EAG/g MS and 22.60 mg EAG/g MS respectively. Fruits of G. coriacea can be considered in this study as a source for phenolic compounds which have beneficial effects on the human organism notably in reducing the risk for development of several pathologies.