A speed change control apparatus for an automatic transmission having a plurality of friction elements in which a gear stage is established by engaging one of the friction elements and disengaging one of the others. The speed change control apparatus includes control valves connected to respective ones of the friction elements, a duty solenoid valve connected to each oil line supplying a respective one of the control valves with control hydraulic pressure, and control means for engaging one friction element by outputting an engagement duty signal to one duty solenoid valve to control the control hydraulic pressure, and disengaging one of the other friction elements correspondingly by outputting disengagement duty signals to one of the other duty solenoid valves to control the control hydraulic pressure.