The present invention discloses a method and a system for operating a motor vehicle brake system being arranged in the following ways: the vehicle has a front and a rear axle and front and rear axle braking mechanisms that act on the wheel at the front and rear axles. The method of the present invention includes steps of: detecting initiation of braking process, detecting current driving speed v, determining initial barking pressure P of the rear brake device, determining pressure to be increased compared with the initial braking press P based on the driving speed v; increasing a target braking pressure [Delta]P to be the braking pressure P; the rear axle braking mechanism being under the control of target braking press P. The present invention further relates to a braking system for a motor.