Core sediments under Rhizophora mucronate, Rhizophora apiculata and Avicennia marina from mangrove forest at Asokaram temple, Samutprakarn in November 2007 were studied to determine total phosphorous and their types (Loosely – P, Al – P , Fe – P and Ca – P). Results showed that total phosphorous in the out side of 3 trees have uncertainly trend and correlative decrease trend while the inside have decrease and have higher than the outside in every level. Loosely – P of these 3 trees was found uncertainly trend while the inside have decrease and have higher than the outside in every level.Fe – P in the outside mangrove forest showed decreased trend as the decrease of the depth while the inside have decrease and have higher than the outside in every level. In this study Al – P and Ca – P were not found at any depth level. Different types of phosphorous were formed depending on types of soil, pH,organic substance collected in soil, distance from the sea and characteristics of intertidal.