An control apparatus for a variable valve mechanism, is capable of executing fail safe control in a case in which locking occurs in either one of a cam shaft of a double shaft structure. The control apparatus for a variable valve mechanism has a cam shaft of a double shaft structure including an outer cam shaft and an inner cam shaft, such that it is possible to adjust the phase of a sub cam of inner cam shaft with respect to an main cam of outer cam shaft, and by means these cams, at least one of an intake valve and an exhaust valve of an internal combustion engine is operated. When an abnormality is detected in one of the cam shafts, the control apparatus controls the phase of the cam of the other cam shaft, in accordance with the determined current phase of the cam.