Seloko Island will be made part of the Batam Island industrial area. This will have an impact on environmental conditions on the island. The purpose of this study was to determine the general condition of the Seloko Island ecosystem. Observed environmental components included: water quality, sediments, mangrove vegetation, seagrass, coral reefs and sediments. The results showed Dissolved oxygen concentrations ranged from 6.5 to 73.3 mg/l; PH ranged from 7.5 to 7.9; Salinity averaged 33.3‰; temperatures ranging from 29.8-30.4°C. Sedimentation, dominant sand. Mangrove diversity consists of Avicennia Alba, Sonneratia alba, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Bruguiera gymnorrhiza, Xylocarpus granatum, and Nypa fruticans. Seagrass cover ranges from 0 to 2.75% with one species, Enhalus acoroides, which describes the condition of seagrass that is not good. Cover of coral reefs ranged from 0 - 0.67%, which illustrates the condition of corals that are not good.