A control system for an automatic transmission of the type having a plurality of friction coupling elements which are selectively locked and unlocked with hydraulic oil to change power transmission paths to place the automatic transmission into desired available gears, a first specific friction coupling element having a locking pressure chamber and an unlocking pressure chamber and being locked when operating oil is charged into only said locking pressure chamber and unlocked when operating oil is coincidentally charged into the locking pressure chamber and said unlocking pressure chamber, and a second specific friction coupling element having a locking/unlocking pressure chamber in communication with the unlocking pressure chamber of the first specific friction coupling element and being locked only when operating oil is supplied into the locking/unlocking pressure chamber. a pressure level Transitional pressure of operating oil is controlled and duration time during a specific gear shift where these specific friction coupling elements are coincidentally locked and unlocked. <IMAGE>
