To provide shift control device and method for an automatic transmission for a vehicle reducing shift shock, even if the number of rotation of an output shaft is changed due to an external influence during an upshift control process.

This device is constituted of a vehicle operation traveling detection means for detecting a vehicle traveling state signal varied and outputted by a traveling state of the vehicle, a shift control means for outputting a prescribed control signal to a vehicle traveling state detecting device, receiving inputs such as a shift mode state of the vehicle outputted by being synchronized according to a control signal, a throttle valve opening, the number of rotation of the output shaft, engine speed, a shift lever position and an acceleration pedal operating state, performing a power on upshift control when a power on upshift signal is impressed during a traveling, controls a relative change rate of turbine rotating speed for turbine rotating speed after the shift during the control process, and performing a power on upshift feedback control, and a driving means duty-controlled by a prescribed shift control duty control signal outputted from the shift control device and performing a shift by supplying/ releasing hydraulic pressure from an oil pump to/from the friction element.