This paper proposes an active mount of naval ships in order to reduce unwanted vibrations. The active mount consists of rubber element and piezostack actuator. To avoid being broken piezostack actuator, the inertial actuator which the piezostack actuator is connected to the inertial mass and rubber element is devised. After describing the configuration of the mount, the active mount system supported by four mounts is then constructed. To attenuate the transmitted vibrations, the feedforward control is designed and experimentally implemented to the system. Vibration control performances such as vertical accelerations are evaluated at each mount and presented in frequency domain.