The present invention discloses a variable valve actuation mechanism, characterized in that movement of a sliding block is controlled for selectively receiving a driving force exerted from an actuating mechanism so as to control lift, such as higher or lower lift, of valves disposed in a combustion engine. With the design disclosed in the present invention, a conventional problem due to misalignment of the channel for locking pin sliding during changing lift of valve is capable of being solved. In the preferred embodiment of the present invention, actuating parts for controlling higher valve lift will not contact with the variable valve actuation mechanism while the valve is under lower lift so that the combustion engine will be operated in an appropriate rotation speed efficiently so as to reduce fuel consumption.