A chitinolytic enzyme-producing bacterium was isolated from sea water on the coast of Busan. The bacterium was identified as Aeromonas sp. based on its morphological, cultural and biochemical characteristics and designated Aeromonas sp. J-5003. The strain produced two chitinoloytic enzymes: chitinase and chitobiase. The optimum culture conditions of the strain for production of chitinoloytic enzymes were investigated. For the production of chitinase, the major components of medium were colloidal chitin $0.5\%$, glucose $0.2\%$, yeast extract $0.25\%$ and peptone $0.25\%$ while for the production of chitobiase, they were colloidal chitin $0.5\%$, galactose and tryptone $0.2\%$. The optimum cultural temperature and initial pH for the production of chitinase and chitobiase were $30^{circ}C$ and pH 7.0, respectively.