The purpose of this research was to know the structure of mangrove vegetation. The research was be conducted in January 2017. The observation of mangrove forest was done in mangrove forest area in Puteri Sembilan Village, North Rupat Sub-district, Bengkalis Regency, Riau Province. The results showed that there were 7 species of mangroves namely: Rhizophora mucronata, Bruguiera gymnorhiza. B. se…