A traction controller for a vehicle having a control system for controlling the driving of driving wheels such that the spin quantities of the driving wheels from a road surface become target spin quantities, a mechanism for correcting a control condition based on the lateral acceleration of the vehicle, calculating the actual turning radius Rr of the vehicle, and calculating the steering angle corresponding turning radius Ri of the vehicle. When a tendency for the vehicle to deviate from a running line having the turning radius Ri is marked at the time of turning, the lateral acceleration of the vehicle is calculated based on the turning radius Ri. Consequently, it is possible to prevent the excessive under-steer state of the vehicle.