A study was conducted in Gunung Basor Forest Reserve, Kelantan in order to estimate the above ground biomass and carbon stock. In this study, the optical remote sensing was used to estimate the above ground biomass and the carbon stock as it is the most standard method by using the measurement of the field data. This study was conducted due to the baseline date of the carbon stock in Gunung Basor Forest Reserve still in the scarcity level where it can be established by using the optical remote sensing images. Based on Normalized Difference Vegetation Index (NDVI) analysis overall, the selected study site of Gunung Basor was merely covered with vast area of dense vegetation. The range of NDVI was between 0.20 to 0.75, where 0.2 — 0.3 referred to grass and shrub whilst 0.5 and above referred as green dense vegetation. The total above ground biomass of Gunung Basor Forest Reserve is 223.2765 Mg/ha. Meanwhile, the carbon stock of the forest is 104.940 Mg C/ha. With the obtained data, it will assist the responsible authorities to manage the forest more efficiently and curb the climate change.