A control apparatus for controlling a step-variable automatic transmission of a vehicle to effect a shifting action of the automatic transmission on the basis of a target throttle valve opening angle for realizing a target vehicle drive force, so as to prevent a shift hunting phenomenon of the automatic transmission. The control apparatus includes a shift permitting portion operable to permit a shifting action of the automatic transmission back to an original speed position prior to a previous shifting action to the present n-th speed position, under the control of a shift control portion on the basis of the target throttle valve opening angle in the present speed position and a vehicle speed, if the previous shifting action to the present n-th speed position has been determined by a shift determining portion on the basis of the vehicle speed V and the target throttle valve opening angle which is calculated by a target-throttle-valve-angle calculating portion to obtain an engine torque to realize a target vehicle drive force set by a target-drive-force-related-value setting portion in the present n-th speed position of the automatic transmission, whereby the shift permitting portion inhibits the shifting action back to the original speed position prior to the previous shifting action under the control of the shift control portion on the basis of the target throttle valve opening angle immediately after the previous shifting action, thereby preventing the shift hunting phenomenon.