The feeding habits of juvenile Chaenogobius annularis were examined based on gut content analysis of 281 individuals, collected from May to June 2011 in the coastal water of Geoje, Korea. Copepods were the main source of food for C. annularis, which constituted 61.6% in IRI. Barnacle larvae was the second largest dietary component. Graphical analysis of the diet composition showed that C. annularis was a specialized predator characterized by strong individual feeding specialization. Both small and large size class of C. annularis mainly consumed harpacticoida and cirripedia cypris.