The authors presented four edaphic factors exert influences on mangrove in Con Dao island: 1/ Topographic and landscape factors of the gulf, which has protecting impacts on the island
2/ The underlying rocks consist mainly of limestone and sand mixed with broken coral, that forming the sediment sea-swamps with shallow and slopping bank. The soils of the swamps are river-born clays with the physical properties and chemical composition responding to the last requirements for the growing of mangrove vegetation
3/ The sea current is main factor that brings about the abundance with biodiversity
4/ The low tidal amplitude, sea wave and salinity are in range of the tropical climate, the low amplitute of temperature variation as well as high precipitation is also the favorite conditions for the development of the mangroves in Con Dao National Park.