Reforestation management goes through the knowledge of the tired out evolution after a forestry rest. The aim of this study was to assess biodi-versity concerning Terminalia superba Engl. & Diels and its undergrowth, and then quantify sequestered carbon stocks to appreciate the impact of reforestation on forest recovery and the enhancement of carbon stocks. The study was conducted at Bilala artificial forest in southeastern Republic of Congo, in Kouilou Department (Mayombe), close to Mvouti District with an altitude of 30 m. The floristic inventory was carried out in 9 rectangular sub-plots of 20 × 25 m each, installed in three blocks of Terminalia superba Engl. & Diels, for a total area of 0.5 ha. These blocks consisted of the 64, 31 and 20 years old plantations. Within ten sub-plots censuses, all trees with a DBH ≥5 cm were identified and measured. 51 trees of Terminalia superba Engl. & Diels and around 3007 trees in its undergrowth have been recorded belonging to 33 botanical families and 52 species. The results showed that the biomass recorded in this forest has been 275 t·ha^﹣1 and the carbon stock was 129.6 t·ha^﹣1. Terminalia superba Engl. Diels had for itself a biomass of 181.42 t·ha^﹣1 out of the 275 t·ha^﹣1 quantified. The amount of CO2 captured in the atmosphere by the recorded floristic procession deducted from this carbon stock was 475.89 tons of CO2, with an economic value equal to US$ 2379.45 or XAF 1,413,278. This study demonstrated that the forestry method of reforestation has a positive impact on biodiversity recovery and carbon sequestration.