Mangroves could potentially contribute to global climate change adaptation and mitigation by absorbing carbon with large amounts and storing it in the sediment and biomass for a long time. The purpose of this study is to estimate the potential stock of carbon and sequestration in conserved and rehabilitated mangroves. It was conducted at four locations including Biduk-Biduk, Karimunjawa, Pati, and Indramayu. The allometric equations method was used to calculate the potency of carbon stock and sequestration in the mangrove. Results show that mangroves in conservation areas have higher carbon stock and sequestration than mangroves in rehabilitated areas. Mangrove in Karimunjawa has higher diversity but the total carbon stock are lower than Biduk- biduk which has total carbon storage of 1,266,997.73 Mg C which potentially absorb 4.65 t CO2e. Total carbon stock in Pati and Indramayu (rehabilitated mangroves) ranged from 2,878.31 to 43,885.63 Mg C which potentially absorb 0.01 to 0.16 t CO2e. Regression analysis showed a positive correlation between mangrove density and carbon stock in conserved and rehabilitated mangroves. The results show that conserved mangroves are more effective in absorbing and storing carbon than rehabilitated mangroves. Monitoring of rehabilitated mangroves is important to maintain and enhance carbon absorption and storage.