ABSTRACT Attempts to mitigate global climate change have brought forestry into focus. Forests absorb carbon dioxide from the atmosphere, alleviate global warming and contribute for rural livelihood. To realize these benefits, there is a need to conserve the existing forests and establish new forests by using different restoration techniques. Information is scarce in Ethiopia on the carbon stock efficiency of the different forest types. The objective of this study was to compare biomass and soil carbon stock potential of a natural forest, exclosure, and Eucalyptus plantation. Systematic and random sampling technique was used for vegetation and soil data sampling. For inventory of vegetation data, 80 plots with plot size of 20m x 20m were used. For soil data collection and sampling of litter, herb and grass, a 1m x 1m sample plot was used. Allometric equations were employed for the calculation of above ground biomass and carbon stock. The mean above ground, below ground, litter and soil carbon stocks for the exclosure were 5.9 ± 19.9, 1.5 ± 5.2, 0.9 ± 0.8 and 123.2 ± 31.4 ton/ha, for the Eucalyptus plantation 11.9 ± 8.0,3.1 ±2.1, 2.6 ± 1.4 and 142.5 ± 37.7 ton/ha and for natural forest 8.3 ± 16.0, 2.2 ± 4.2, 3.3 ± 1.2 and 181.6 ± 46.7 ton/ha respectively. The total mean carbon stock for exclosure was 131.6 ± 45.5 ton/ha, for plantation 160.1 ± 35.8 ton/ha and for natural forest 195.3 ± 58.3 ton/ha. The carbon stocks in each pool exhibited distinct patterns between the forest types. The above ground, below ground and soil organic carbon stock increased in the natural forests and plantation, while the litter carbon stock showed decreasing towards the exclosure. Higher amount of aboveground carbon in plantation forest and soil carbon stock found in the natural forest. In total natural forests store high amount of carbon, this can play an important role in climate change mitigation. The carbon pool variation between different forest types was significant at (P < 0.05); however, there was no significance difference between forest types by aboveground and belowground biomass. Therefore, climate change mitigation measures should consider expanding exclosure with the same priority as conserving natural forest and increasing plantation forests. Keywords: Natural forest, Plantation forest, Exclosure, Carbon stock and sequestration, Climate change.