A braking force distribution control device is provided in which wheel speeds of respective wheels of a vehicle are detected. On the basis of the detected wheel speeds, slopes of coefficients of friction μ between the wheels and a road surface are estimated as road surface μ slope values of the respective wheels. On the basis of the estimated road surface μ slope values of the respective wheels, braking forces of the respective wheels are controlled such that the braking forces among the respective wheels are adjusted.