The Ranong mangrove forest ecosystems located on the Andaman sea coast of Thailand was studied using the Point Centered Quarter (PCQ) method to determine the mangrove vegetation and the dominant mangrove species. Mangrove cluster was evaluated using cluster analysis, specifically the standardized relative Euclidean distance method. Seven zones were identified and named after the dominant species: Zone I) Rhizophora apiculata - Xylocarpus granatum, Zone II) Rhizophora apiculata - Ceriops decandra, Zone III) Avicennia officinalis, Zone IV) Avicennia marina, Zone V) Rhizophora apiculata - Rhizophora mucronata, Zone VI) Rhizophora apiculata - Avicennia officinalis and Zone VII) Rhizophora apiculata. We recommend that the dominants should be utilized in mangrove reforestation of the ravaged mangrove ecosystem following the recent tragic tsunami in the Andaman Sea.