In major low-frequency vehicle vibration phenomena, such as shake and idle vibration, engine mounts play an important. To reduce shaking, the engine mounts must suppress Vibration by increasing their damping. In addition, in an idle state, the engine mounts should be soft enough to isolate the engine vibration from the vehicle body structure. These two requirements are difficult to be achieved in conventional engine mount design. This paper presents a new design method for solving the above-mentioned problem. Two key elements are used in this new method. The first is the phase control on vibration transmission utilizing the fluid resonance in the hydraulic engine mounts. The other in the vector synthesis approach in treating multiple vibration input to the vehicle body.