The biology of spotted-carp, Hemibarbus maculatus in Tai Hu, had been inve-stigated mainly from March 1964 to February 1965 and partially in 1978 and 1982. 1,614 spee.imens were examined. A brief analyses of the rational exploitation of its resources is proporsed Spotted-carp belongs to subfamily Gobioninac family Cyprinidae.They inhalait widely in the main inland waters in China. It is one of the commercial important fish ixt Tai Hu. Age and growth, feeding, spawning habits and embryonic development of the fish w ere studied . Age of the fish can be determined by the annual rings on the scales, and it has revealed that the annual rings are formed during May to September each year. The weigh-length relationship of this fish may be represented by the following formula:W=0.05769L^2.4987. In the growth, the increase of length is faster in the first two years tb.an the increase of weight, but later an it is reversed. The largest speezmen collected male is 2S .8 em in length, 295 g in weight，female is 26 .2 cm in length, 285 g in w eight. The adult fish feeds mainly on aquatic invertebrates, such as shrimps, small molluscs (clam, snails, etc.)，among which shrimps seem most favorable. The fish attaixis sex maturity at two years of age. Breeding season is April to May.Eggs are sticky deposited on submerged aquatic plants. Fertilized eggs require about 4 days to hatch at a temperature 15-21℃. Lastly,a discussion on the rational exploitation of the stocks in order to maintain a sustaining fisheries in Tai Hu is proposed.