A novel marine esterase-producing bacteria isolated from the Bohai Sea sediment was identified as Bacillus licheniformis.The MP-2 esterase was primarily purified and characterized.The optimal range of temperature of the esterase was 50~70 ℃,and the maximum activity was achieved at 60 ℃ and pH10.0.The esterase was alkaline and its optimum range of pH was narrow.The thermal stability of the esterase was good.Co2+,Li+ions were found to activate the esterase,but Ca2+ had no significant effects on the activity of the esterase.While SDS,EDTA and Tween-20 had significantly suppressive effects on the esterase.It showed strong resistance to ordinary organic solvents.The enzyme exhibited different esterase activities towards substrates with different length of carbon chains.