Mangkunagoro I Forest Park is a nature conservation area for plant collection purposes and preserving biodiversity. Moreover, Forest park as a forest also can absorb and store carbon as biomass. It makes forest park play a role in the mitigation of climate change. This research aimed to determine the amount of carbon stock in the Mangkunagoro I Forest Park collection zone. There are 35 plots in total with 20 x 20 m in size taken using systematic sampling. A non-destructive method with allometric equations was used to estimate total biomass and carbon stocks. In the Mangkunagoro I forest park collection zone, 11 species of trees and 3 species of bamboo were found with a total density of 79 trees/ha. Estimated biomass, carbon stocks, and carbon sequestration in the site were 304.24 ton/ha, 142 ton/ha, and 299.68 ton/ha, respectively.