Introduction: Chitinases are enzymes that hydrolyze the internal ?-1,4 glycosidic linkages of chitin, a significant structural component of arthropod exoskeletons and fungus cell walls. Objective: Main objective of current study was to determine the protein and to check the antimicrobial, antifungal activity of chitinase in Bacillus salmalaya strain 139SI. Methodology: Purified and estimation enzymes were quantified by the method of Lowry method. Antimicrobial action of chitinase was done using standard Disc Diffusion method while the hyphal extension inhibition assay was used to test the antifungal activity of pure chitinase strains 139SI, 140SI, and 141SI. Results: In this study, Bacillus salmalaya 139SIexhibited strong hemolytic activity and their protein concentration was measured as 56.43 mg/mL. In addition, strain 139SI had strong antifungal activity against phytopathogenic fungus including Fusarium sp., R. solani and Phytophthora sp. Strain 139SI had the capability in degrading the peptidoglycan component of cell walls of gram-negative bacteria such as Escherichia coli but not against the gram-positive, Staphylococcus aureus. Chitinase activity was observed when 200?l crude extract of 139SI able to degrade 0.09 g chitin of shrimp shell by breaking down shrimp shell structure and bonds of chitin effectively as early as 2 days or up to 7 days. Conclusion: Hence, based on the results, B. salmalaya 139SI has potential to be a novel biofunctional chitinase that could use as a biological agent in degrading the chitin component of fungal cell walls and shells waste of many kind of insect and crustaceans for solving future problem in the agricultural sector and fishery industry.