An engine system may include an engine including first and second cylinder banks; a throttle valve; a first exhaust manifold gathering exhaust gas exhausted from the first cylinder bank to be supplied to the first exhaust line; a second exhaust manifold gathering exhaust gas exhausted from the second cylinder bank to be supplied to the second exhaust line; a turbocharger including a turbine rotated by the exhaust gas exhausted through the first exhaust manifold and a compressor rotated in connection with the turbine; a cylinder deactivation (CDA) device selectively deactivating the cylinders of the first cylinder bank; and a supercharger including a motor and an electric compressor operated by the motor.