Seagrass is a unique angiosperm that grows in the sea. It is one of the three ecosystems that linked each other that equilibrate marine coastal environment. The increased rate of the destruction of the seagrass meadow calls an alarming threat to the anthropogenic community. The study determined the percentage cover and diversity of indexes of the seagrass in Igang Bay before the anthropogenic threat happened. Line transect – quadrat method was used and analyzed using Kruskal-Wallis test and Mann-Whitney test before subjected to similarity and overlap attribute, diversity, maximum diversity, evenness and dominance indexes. There are nine species of seagrasses. Th ese species are all found in the eastern sites. While three of them are also found in western sites. Canopy height and percent cover of sea grass has inverse interaction. Index of similarity between two sites is 0.3333 and 0.4286 for overlap attribute. Eastern site has higher diversity index and February is the highest at 1.24 and 2.10 in maximum diversity. The sea grass distribution is even after inter-monsoon at 0.71 and 0.12 in Eastern site and Western site, respectively. Thalassia hemprichii is the dominant species at both sites, and peak at July at both sites. In general, the Igang Bay seagrass meadow is Thalassia mixed meadow.