A power-supply control apparatus of a vehicle comprises a first electricity-storage device to supply electric power to a starter for starting engine, a generator to convert kinetic energy of the vehicle during a vehicle deceleration to electric energy for energy recovery, a second electricity-storage device coupled to the generator to store the electric power from the generator thereat, a feeder circuit coupling the second electricity-storage device to an electric load with a relatively-small electric-load capacity via a DC/DC convertor, a coupling line coupling the second electricity-storage device to the first electricity-storage device via a coupling relay, and a controller to control the electric power passing through the feeder circuit and the coupling line, wherein the controller executes a control to make the coupling relay on the coupling line in an OFF state when the starter operates.