In speed ratio control apparatus and method for a hybrid transmission, an integrated controller calculates a speed ratio manipulated variable in accordance with a deviation between a speed ratio representative command value and a speed ratio representative actually measured value. Then the controller calculates a speed ratio purpose component command value for each drivingly input element torque which is drivingly inputted to a differential mechanism of the hybrid transmission according to the calculated speed ratio manipulated variable, an acceleration ratio of each drivingly input element in a shift motion, and an inertia of each drivingly input element in the shift motion. Then, the controller outputs each calculated speed ratio purpose component command value to a torque actuator of the corresponding drivingly input element.