In this apparatus, maintaining control (time t1 to t2) which instructs fixing of the open timing VVT of an intake valve is executed in a predetermined low load state. Subsequently, there are executed changing control which instructs changing of the open timing VVT by a predetermined amount (time t2), and maintaining control which again instructs fixing of the open timing VVT of the intake valve (time t2 to t3). An intake-valve control apparatus is determined to be “anomalous” when an change amount Δave (=ave2−ave1) between the average ave1 of a large number of sample values of ΔMFBβ (combustion percentage increase amount within a predetermined crank angle range in an expansion stroke) during the maintaining control before execution of the changing control and the average ave2 of a large number of sample values of ΔMFBβ during the maintaining control after execution of the changing control is less than a predetermined value C.