An actuator for a valve lift controller linearly driving a control shaft of a changing mechanism comprises a feed screw mechanism including a screwed shaft linearly moving along with the control shaft, and a rotation spindle rotating coaxially with the screwed shaft. The feed screw mechanism converts a rotational movement of the rotation spindle into a linear movement of the screwed shaft. Moreover, the actuator comprises a unit attached to the rotation spindle, an electric power distributor located at an opposite side of the screw mechanism relative to the changing mechanism, and an stopper member restricting a movement of the unit in the axial direction from an electric power distributor to the unit.