Tree species play a very important role in storing and sequestration of carbon by preventing the accumulation of carbon dioxide in the atmosphere as greenhouse gases. Carbon stock assessment is a useful tool in estimation of the importance of an area in terms of its carbon storage capacity. The study revealed that the ultramafic forest in Sitio Dicasalarin, Baler, Aurora, Philippines is a critically important area with tremendous carbon storage capacity mainly contributed by the endemic and threatened species as found.