This study was conducted in October 2019, was located in Mangrove Forest Area Ujuang Labuang Ujuang Labuang Agam, West Sumatera. This study aims to understand community structure of epiphytic diatoms on the roots Rhizophora apiculata. The method used in this study was a survey method. The results showed that there were 18 epiphytic diatom genera in the roots of R. apiculata, dominated by t…