Abstract:Bio-floc technology was applied in closed culture system of Litopenaeus vannamei. The optimum carbon source and its addition for bio-floc culture was screened, and the optimum carbon addition and stocking density of L. vannamei was determined. Results showed that in closed culture system of L. vannamei at the stocking density of 150 and 300 PL/m2, sucrose was added in the quantity of 77% feed (containing 42% protein) everyday, bio-floc formed on the 4th day post stocking. During the 84 d culture period, the ammonia-N and nitrite-N concentrations kept at very low levels, and the shrimp survival rate was above 80%, which means better harvest of L. vannamei in bio-floc culture system.