The aims of the present study were to purify, characterize and evaluate anticancer activity of l-arginase against cancer cell lines. The cells of the marine bacterial species were entrapped in hybrid beads made up of PVA and sodium alginate. And the production of enzyme was carried out using immobilized cells of idiomarina sp. (Gene Bank Accession Number JF346667) in a sea water based mineral arginine medium. The enzyme thus obtained was purified to near homogeneity (29.87 fold) with a molecular weight of 37 k Da. It showed an optimal pH and temperature of about 8 and 35 0 C. When compared to other metal ions, manganese was the most efficient metal ion for enzyme activity. Whereas other ions were found to repress the activity. Out of various substrates used, l-arginase showed highest substrate specificity for l-arginine. The enzyme was strongly inhibited by thiol compounds such as dithiothrietol, reducing agents like 2-mercaptoethanol, and chelating agents like EDTA. The yield of the enzyme thus produced from the immobilized cells were almost near to the yield obtained from that of the free cells. Hence cell immobilization technology can be adopted for the enzyme production. Of the various other methods adopted, use of PVA- sodium alginate beads were considered as a suitable one .The purified enzyme showed good range of activity against Hela cells with IC50 value 0.5U/ml. Hence, l-arginase can be a potential candidate as an anticancer agent.