Valve operation control device for internal combustion engine

A valve operation control device for an internal combustion engine having a valve operation mode changing mechanism for switching the opening/closing operation of an intake or exhaust valve between a low-speed operation mode corresponding to a low-speed operation of the engine and a high-speed operation mode corresponding to a high-speed operation of the engine, and control means for controlling the operation of the valve operation mode changing mechanism according to the rotational speed of the engine, comprising, a rotational speed detector for detecting the rotational speed of the engine connected to said control means, said control means having a first rotational speed setting that is substantially equal to a rotational speed at which the output torque of the engine remains the same in the low- and high-speed operation modes of the valve operation mode changing mechanism for said control means to cause shifting of the valve operation mode changing mechanism from the high-speed operation mode to the low-speed operation mode, and said control means having a second rotational speed setting higher than the first rotational speed for causing of the valve operation mode changing mechanism from the low-speed operation mode to the high-speed operation mode.