Halophilic Pseudomonas sp.W7 isolated from laver in the southem sea of Korea showed alginate lyase activity. Gene (aly) encoding alginate lyase was cloned in E.coli JM83 and the N-terminal amino acid sequence of the enzyme was determined after purificaion. The recombinant enzyme has been shown to have a molecular weight of about 40kDa after 12% SDS-polyacrylamide gel electrophoresis.