Seabass-Lates calcarifer is a suitable and effective object to raise in abandoned shrimp pond. Seabass farming will solves rotating and breaking crops problem, diversifies raising object, increase productivity and effect on the same cultivated areas. During period of 2009-2010, the authors accomplished raising sea bass in brackish ponds in Hai Phong following two forms: monoculture and polyculture with lilapia. After eight months, the initially weight of sea bass had increased from 7-8 gram to over 700 gram per fish, survival rate had obtained over 85 percent. In the sea bass monoculture model, survival rate obtained 85.6 percent, feed ratio (FR) averaged 6.65 percent, the value of average net profit of each crop reached 41 million VND per ha
in the Seabass polyculture with tilapia
survival rate of sea bass reached 87.2 percent, feed ratio averaged 6.86 percent, the average net income of each crop was 48 million VND per ha.