A variable linked braking system controlled by motorcycle speed includes a brake master cylinder; a hydraulic pressure proportion variable valve connected to the brake master cylinder by an oil path; front and rear brake units connected to the hydraulic pressure proportion variable valve by first and second oil paths, respectively; a hydraulic pressure proportion controller for controlling the hydraulic pressure proportion variable valve; a motorcycle speed sensor for converting a sensed motorcycle speed into a speed signal and sending the speed signal to the hydraulic pressure proportion controller; and a brake switch for starting the brake master cylinder and sending a brake signal to the hydraulic pressure proportion controller for controlling the hydraulic pressure distribution proportion of the hydraulic pressure proportion variable valve so that the ratio of braking force of the front brake unit to braking force of the rear brake unit increases with the motorcycle speed.