Estimation of total carbon stock in any forest is very important as it provides ecological as well as economic benefits through various environmental services. The study was carried out to quantify the vegetation and soil carbon stock of natural Chirpine (Pinus roxburghii) forest of in sub-tropical region of Makawanpur district, Nepal. The inventory of estimating above and below ground biomass of forest was carried out using stratified random sampling method Forest biomass was calculated using standard allometric models. Soil samples were taken from soil profile up to 40 cm depth at the interval of 20 cm. Walkey and Black method (1934) was used for measuring soil organic carbon. Total amount of carbon stock in Pinus roxburghii forest was 213.05 t/ha with above ground carbon stock 140. 56 t/ha, below ground carbon stock 27.14 t/ha and soil organic carbon 45.35 t/ha respectively. Total carbon stock in Pinus roxburghii forest was composed of 66% for above ground, 21% by the soil and 13% by below ground. The study concluded that forest types and soil play an important role on total carbon sequestration. Hence, the goal of reducing carbon sources and increasing the carbon sink can be achieved efficiently by protecting and conserving the carbon pools in existing forests ecosystem.