Efforts to mitigate climate change by utilizing marine vegetation as a blue carbon absorber are currently being intensified, one of which is macroalgae vegetation. This research was conducted in March-May 2018, with the aim to know how much different is the carbon absorption and storage potential between Gracilaria verrucosa and Halimeda opuntia in Muara Binuangeun, Banten. The result showed that the average carbon adsorption potential of G. verrucosa and H. opuntia was 228.73 gC/m2/day and 1500.57 gC/m2/day, respectively, while the average carbon storage potential were respectively 135.29 gC/m2/day and 217.01 gC/m2/day. The carbon content of G. verrucosa was 4.47% while H. opuntia was 4.64%. Based on the analysis of T test results, the potential of H. opuntia carbon adsorption was significantly higher than G. verrucosa and the carbon storage of H. opuntia was higher than G. verrucosa but not significant. In addition, ash content in H. opuntia is higher than G. verrucosa and H. opuntia water content is lower than G. verrucosa. It is because H. opuntia stores more carbon in the form of calcium carbonate. Therefore, conservation efforts should be made for H. opuntia species which have the higher potential and contribution to reduce car