A vehicle braking system includes: a hydraulic booster (13) which applies output hydraulic pressure of a hydraulic power source (12) to a boosted hydraulic pressure chamber (25) after regulating the output hydraulic pressure as a control piston (90) operates to balance reaction force generated by hydraulic pressure of the boosted hydraulic pressure chamber (25) with brake operating input; and a brake stroke simulator (14) installed between the brake operating member (11) and the control piston (90) in order for a driver to feel operating strokes of the brake operating member (11). The brake stroke simulator (14) has: an input member (166) axially slidably housed in the control piston (90) of a cylindrical shape and linked to the brake operating member (11); and an elastic body (167,167') interposed between the input member (11) and the control piston (90). The elastic body (167,167') is formed into a tubular shape so as to come into resilient contact with an inner circumference of the control piston (90) by expanding its diameter under the action of axial compressive force generatedby forward movement of the input member (166). Consequently, the brake stroke simulator (14) allows large hysteresis width in relationship between brake operating stroke and operating load.