A control apparatus for an automatic transmission includes an operational condition detecting unit for detecting a vehicle operational condition, a slope detecting unit for detecting a road surface slope, and a shift characteristic selecting unit for selecting one of a plurality of shift maps preliminarily set according to the road surface slope. The control apparatus further includes an acceleration/deceleration calculating unit for calculating an acceleration or deceleration from the degree of increase or decrease in vehicle speed per unit time, a deceleration shift characteristic for deciding a gear position according to the deceleration and the vehicle speed, and a brake detecting unit for detecting a brake operation. When the road surface slope is determined to be a downhill slope and the brake operation is detected, the selected shift map is changed to the deceleration shift characteristic and the gear position is decided according to the deceleration shift characteristic.