A hydraulic brake system includes a braking state switching device which selectively realizes: a high-pressure-source-pressure dependent braking state in which a brake force is generated with a magnitude that depends on a pressure of brake fluid supplied from a high-pressure-source device; and an operation-force/high-pressure-source-pressure dependent braking state in which a brake force can be generated with a magnitude that depends on both of the pressure of the brake fluid supplied from the high-pressure-source device and a brake operation force of a driver which is applied to a brake operating member and that is larger than the magnitude of a brake force which can be generated in the high-pressure-source-pressure dependent braking state. The brake system may be equipped with a high-pressure-source device having a relatively small capacity, thereby allowing the high-pressure-source device to be compact and low-cost.