Several bacterial strains utilizing crude oil as their sole carbon and energy source were isolated from polluted marine by crude oil. One of the strains, named KCL-2 showed strong degradation activity for crude oil. This strain was identified as a Klebsiella sp. based on the morphological, biochemical, and physiological characteristics. The optimum cultural conditions were as follows; $27^{circ}C$~$37^{circ}C$ for temperature and 7.0 for initial pH. Additionally, the optimal concentration of sodium chloride was 3.0%, confirming indicating that this strain was derived from sea water.The strain KCL-2 could use several kinds of n-alkane hydrocarbones from octadecane to octacosane as a sole carbon source. The emulsifying activity by KCL-2 was the highest after 3 days of cultivation under the condition of 3.0% sodium chloride, pH 7.0 and 32$^{circ}C$. This strain had several criptic plasmids.