To accomplish both of prevention of a spin and sure acquisition of a braking force by performing control so that a rear wheel braking force is relatively increased during turning traveling on a high μ road as against that during turning traveling on a low μ road.

Braking force distribution control in a step 112 is finished when three decisions in steps 113-115 are normally executed and continued and the predetermined condition is satisfied in each of the decisions. It is determined whether or not a road surface is a low μ road surface, and a road surface μis determined on the basis of an Rr relative slip ratio to a front wheel slip ratio during a braking force distribution control, and its absolute value is high on a low μ road, while its absolute vale is low on a low μ road. A low μ road is determined if the road surface μ is the predetermined vale or less, while a high μ road is determined if the road surface μ is the predetermined value or more. On the low μ road, the step 112 is executed unless conditions in the steps 113 114 are satisfied, and a spin in turning traveling on the low μ road is suppressed. Contrarily, when the high μ road is determined, process is transferred to a step 116, and a braking force for turning traveling on the high μroad is secured.