A four-wheel drive force distribution apparatus for distributing drive forces to the wheels of a four-wheel drive vehicle, in which the distribution of drive force to the front inside wheel (2a) and the distribution of drive force to the rear inside wheel (3a) are adjusted based on a ground load of the front inside wheel (2a) and a ground load of the rear inside wheel (3a) when the vehicle is turning, and the distribution of drive force to the front inside wheel (2a) compared with distribution of drive force to the rear inside wheel (3a) is reduced the smaller the ratio of the ground load of the front inside wheel (2a) to the ground load of the rear inside wheel (3a) during turning.