A shift control system for an automatic transmission including a shift gear mechanism for providing a plurality of shift stages of different speed ratios, a plurality of frictional elements (41-46) to be selectively actuated for switching a power transmitting path to establish a desired shift stage, range selecting device for selecting a shift range at least between a forward and a reverse ranges through a manual operation of a driver, control device for providing the shift gear mechanism with a specific shift stage in which an input member (1) and output member (14) of the shift gear mechanism are rotated together with each other in the case where the reverse range is selected during a forward movement and thereafter a forward range is selected again, the specific shift stage being provided for a predetermined time period after the forward range is selected again. A double lock condition of the shift gear mechanism can be avoided. <IMAGE>