Mangroves are distributed in intertidal zones of coastal environments or estuarine margins, playing a critical role in the global carbon cycle. However, understanding of the carbon cycle role of mangrove associates in the Republic of Korea is still limited. This research measured soil respiration and leaf gas exchange in three habitats of Hibiscus hamabo (Gimnyeong, Seongsan, and Wimi) and analyzed the impacts on sites and months. Soil respiration was measured once a month from June to October 2022 and leaf gas exchange was measured monthly from June to September 2022. Soil respiration in August (5.7±0.8 μmol CO2 m-2 s-1) was significantly higher than that in other months (p<0.001) and soil respiration increased as air temperature increased (p<0.001). In Seongsan, net photosynthesis in July (9.0±0.9 μmol m-2 s-1) was significantly higher than that in other months (p<0.001). Net photosynthesis increased as stomatal conductance and transpiration rate increased during the entire period (p<0.001). Furthermore, a weak positive linear relationship was observed between soil respiration and net photosynthesis (r2=0.12; p<0.01). The results indicated that soil respiration was influenced not only by air temperature and season but also by net photosynthesis. This study is expected to provide basic information on the carbon dynamics of mangrove associates.