A method of controlling traveling of a vehicle may include a measuring step that measures a longitudinal acceleration sensing value by a longitudinal acceleration sensor on a vehicle, a longitudinal acceleration calculating step that calculates a longitudinal acceleration of the vehicle from a speed of the vehicle, a slope degree calculating step that calculates a slope degree of a ground on which the vehicle is, from the longitudinal acceleration sensing value and the calculated longitudinal acceleration, a determining step that determines a slope direction and a slope level of the ground from the calculated slope degree, and a controlling step that provides in advance a torque amount, which is distributed from main driving wheels to sub-driving wheels for traveling, to a power distribution device, at different levels in accordance with the slope direction and the slope level of the ground.