Sea stars play an important role in food webs, generally as predators and detritus feeder. This research has been conducted in December 2011 β March 2012. This research is subjected to achieved its biodiversity in the Karimunjawa Islands. Samples were collected from western and eastern side of Karimunjawa Island, western side of Menjangan Kecil, northern side of Cemara Kecil and northern side of Cemara Besar island, up to the depth of three meters. Species identification was done at Biology Laboratory of the Research Center for Oceanography (P2O-LIPI) Jakarta. A total of 11 asteroid individuals belonging to 9 species of 6 genera, which represented 4 families and 2 orders have been identified. Most of sea stars were found on the coral reef. Based on morphological characters of sea stars that apparently similar, even living in the same location, however after identified are different species, that is Archaster angulatus and Archaster typicus, Nardoa frianti and Nardoa pauciforis then Linckia laevigata and Linckia multifora. All species was considered common for tropical Indo Pasific region, including Indonesian water