To suppress the worsening of control performance with the generation of vibration when feedback controlling a variable valve system.

In this control device for the variable valve system for changing the valve operating property (a valve lifting amount) of an intake valve or an exhaust valve for an engine, a controller 301 sets a first manipulated variable U1 in accordance with a deviation between target valve operating property (TGVEL) and detected valve operating property (VCS_ANGL). By using a low pass filter 302 for processing the detected valve operating property (VCS_ANGL), its vibration center position is detected. An auxiliary controller 303 sets a second manipulated variable U2 in accordance with a deviation between the target valve operating property (TGVEL) and the detected vibration center position. An addition part 304 adds a second manipulated variable U2 to the first manipulated variable U1 to find a final feedback manipulated variable U which is output.