Ecophysiological attributes of Rhizophora apiculata Blume, and its two congeners occurring in the same habitats in Can Gio Mangrove forest were studied in order to determine the differences in their mechanisms of response to environment. The results showed that in the same favorable condition of the study area, Rhizophora apiculata Blume, is healthier and has higher photosynthetic rates and light absorbing ability than those of Rhizophora stylosa Griff, and Rhizophora mucronata Lamk. These factors help Rhizophora apiculata Blume, to grow rapidly, and therefore dominate the forest canopy. However, as a trade-off, these attributes also may account for the higher sensitivities of Rhizophora apiculata Blume, growing under favorable conditions in the study area to extreme environmental stresses, which occurs in the very short time, only some hours while the air temperature is very high and the tide low; this may explain stochastic deaths observed for local Rhizophora apiculata Blume, stands. This phenomenon does not happen with Rhizophora apiculata Blume, growing in areas with unfavorable conditions. Meanwhile, Rhizophora stylosa Griff, and Rhizophora mucronata Lamk. have lower rates of photosynthesis and reduced leaf morphology, which help them have a wider range of adaptation to environmental conditions. In fact, these two species are less competitive than Rhizophora apiculata Blume, in the survey area but are widely distributed in harsher conditions.