The growth and estimated production of Acanthogobius flavimanus (1.9~24.7 cm TL) were investigated in an eelgrass bed and unvegetated tidal flat of Dongdae Bay, Korea from March 2006 to February 2007. Growth in fish total length was expressed by the von Bertalanffy’s growth equation as: L_t=43.238(1-e^{−0.3138(t+0.2507)}). Estimated densities, biomass, daily, annual production and P/B ratio were higher at eelgrass bed than those of at unvegetated tidal flat. Monthly variation in daily production was large; the peak numbers occurred in November 2006 (0.0014 g/m²/day) at eelgrass bed, whereas was 0.002 g/m²/day in July 2006 at unvegetated tidal flat. The eelgrass bed has been supported to maintain capacity of higher production of A. flavimanus than those of in unvegetated tidal flat.