In recent years, high performance engines and the reduction in engine room due to aerodynamic styling has caused increases in engine room temperature. Because of this increasing temperature, the conventional natural rubber engine mount is now at the marginal point on its performance and durability. Several heat resistant materials have been considered for engine mount applications because of this reason. Polychloroprene rubber could be a strong candidate for engine mount application due to its balance of heat resistance, dynamic properties, and fatigue life. This paper will discuss the development of the technology, property characteristics and part performance simulations on the HYUNDAI BUSH TYPE COMPLEX ENGINE MOUNT (for 2.0L DOHC ENGINE). This type of mount requires higher creep resistance and fatigue life than those of other designs, such as block or simple shear type mounts. Early evaluations of polychloroprene mounts have shown some deficiencies in creep resistance. Therefore to adress this concern, the design and formulation development to overcome the initial lack of creep resistance of polychloroprene are shown. Also, the effect of heat aging on dynamic characteristics and performance are investigated. All the test results are compared with those of natural rubber mounts. The results will show the possibility of the first application of polychloroprene rubber on this type engine mount giving improved fatigue life even after heat aging with balanced dynamic properties.