The coral reef at Chiriatapu is a leeward fringing reef with a tropical oceanographic setting. Surveys of reef corals at Chiriatapu were done with respect to species composition and zonation. Data from this survey records 38 species from 13 families, 12 are new records from this region. The new records now raise the total number of reported reef coral genera and subgenera from 31 to 36 (including soft corals). The distribution and zonation are largely controlled by an ecological grid, modulated by such parameters as space, light, salinity, water motion and nutrients, while the succession of major types follow the hydrodynamic gradient and the energy changes of the sea (Porites-Acropora-Pocillopora series). This colonization pattern seems to be regulated through growth gradients of species based on ‘r’ and ‘k’ selection. Indo-Pacific species belonging to the genera Pocillopora, Acoropora, Porites, Montipora, Favia and Fungia account for much of the coral coverage and the assemblage shows consistency in distribution with Indo-Pacific reefs. A striking feature is the abundance of octocorals which have been selected the channel slops as their niche.