Square meter quadrat samples harvested monthly during 1971 to 1972 provided data on the species composition, standing stock, and net primary aerial production of a salt marsh community in St. Louis Bay Estuary, Mississippi. Although a total of 34 species of marsh plants were identified,Juncus roemerianus, Spartina cynosuroides, Scirpus americanus andDistichlis spicata were found to be the most dominant in all the quadrats sampled. Maximum biomass of alive, dead, and partially decayed plants were observed in July, August and January respectively. Community annual net production estimated by harvest method was 1051 g dry wt m−2 or 5012 ash-free Kcal m−2. Total biomass obtained by reharvesting previously clipped quadrats in various ages of regrowth revealed a seasonal pattern of growth rate with a maximum during late summer and a productivity estimation of 1108 g dry wt m−2 or 5541 ash-free Kcal m−2.