The control system for an automatic transmission may include, a detecting portion of driving information adapted to detect the driving information including a temperature of an engine coolant, temperature of a transmission oil, a positional change of an accelerator pedal, a current shift-speed, and driving speed. a control portion adapted to determine a virtual positional change of the accelerator pedal based on an actual positional change of the accelerator pedal and a tip-in speed transmitted from the detecting portion of driving information, to determine a target shift-speed according to the actual positional change of the accelerator pedal or the virtual positional change of the accelerator pedal and the driving speed, and to control a shift to the target shift-speed. an actuator adapted to engage the target shift-speed according to a control signal received from the control portion.