Exhaust gas odor in DI diesel engines is reduced mainly by improvement of in-cylinder combustion and by catalytic converter. In this study, the effect of high-pressure injection and an oxidation catalyst on the exhaust odor was investigated by engine with common rail high pressure injection system. At idling condition an injection pressure of 60∼80 MPa showed minimum exhaust odor, total hydrocarbon (THC) and the least aldehyde. However the odor reduction by high-pressure injection is not sufficient. The preconditioned catalyst aging under the high temperature reduces exhaust components and odor just after starting due to good adsorption. At the catalyst temperature above 200°C, there were remarkable reductions of odor, but bellow 200°C, objectionable exhaust odor appears sharply.