The fermentation conditions of an agar-degrading bacterium NBRC102603 isolated from the coastal water were optimized by using orthogonal experiment.The optimum condition for agarase production consisted of peptone 5.0g/L,yeast extract 1.25 g/L,agar 4.0g/L,1 % inoculating quantity,rate of shaking flask with 100 mL liquid in a 500 mL flask was 150 r /min.After 48h fermentation at 28℃,the enzyme activity was 58.94U/mL,which was 2.08 times higher than before optimization.After a serious of purification processes,two types of purified agarases of NBRC102603 were obtained,identified as agarase A and agarase B.Agarase A was purified 17.29-fold,with a specific activity of 870.51U/mg;while B was purified 16.65-fold,with a specific activity of 838.39U/mg.The purified enzyme A and B appeared to be homogeneous under the inspection of SDS-PAGE,and they had molecular masses about 83.6 ku and 36.8 ku.