A vehicular drive system switchable between a continuously-variable and step-variable shifting states, and a control device for controlling the vehicular drive system so as to reduce a shifting shock of an automatic transmission included in the drive system, which takes place due to an overlap control involving a switching control of the drive system and a shifting control of the automatic transmission.Execution-timing control means 82 is provided to command switching control means 50 and step-variable shifting control means 54 to sequentially execute a switching control by the switching control means to switch transmission mechanism 10 between an electrically established continuously-variable shifting state and a step-variable shifting state, and a shifting control by the step-variable shifting control means to shift an automatic transmission portion 20, even when an overlap control involving the switching control and the shifting control is required, whereby the switching and shifting controls can be rapidly completed. Since the transmission mechanism 10 is not switched during the shifting control of the automatic transmission portion 20, the input speed of the automatic transmission portion 20 will not change due to the switching control, apart from a change of the input speed as a result of the shifting control, making it possible to prevent the complicated shifting control and reduce the consequent shifting shock.