A valve train apparatus of 4 stroke-cycle internal combustion engine includes an intake cam shaft, an exhaust cam shaft, an eccentric cam shaft, an intermediate lever, a rocker arm, and an intake valve. A lift of the intake valve is continuously varied by controlling rotations of the intake cam shaft and the eccentric cam shaft via the intermediate lever contacting the intake cam shaft and the eccentric cam shaft, and via the rocker arm contacting the intermediate lever. At least two of a parting surface of a bearing of the eccentric cam shaft, a parting surface of a bearing of the intake cam shaft, and a parting surface of a bearing of the exhaust cam shaft are arranged on a coplanar surface.