A vehicle traveling control method comprising: determining a driver's intention for acceleration during vehicle traveling; predicting, when it is determined that the driver has no intention for acceleration, which is superior between a first fuel consumption reduction effect by inertial traveling and a second fuel consumption reduction effect by deceleration energy regeneration, the inertial traveling making the vehicle travel, with power transmission disconnected between an engine and a drive wheel (6a, 6b) of the vehicle, and the deceleration energy regeneration inputting rotational power of the drive wheel (6a, 6b) of the vehicle to an electric motor; performing inertial traveling when it is predicted that the first fuel consumption reduction effect by inertial traveling is superior to the second fuel consumption reduction effect by deceleration energy regeneration; and performing deceleration energy regeneration when it is predicted that the first fuel consumption reduction effect by inertial traveling is not superior to the second fuel consumption reduction effect by deceleration energy regeneration, characterized in that the vehicle traveling control method further comprises: detecting a speed (Vv) of the vehicle upon determining that the driver has no intention for acceleration; wherein it is predicted, when the speed (Vv) is equal to or higher than a speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is superior to the second fuel consumption reduction effect by deceleration energy regeneration, and when the speed (Vv) is less than the speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is not superior to the second fuel consumption reduction effect by deceleration energy regeneration. determining a driver's intention for acceleration during vehicle traveling; predicting, when it is determined that the driver has no intention for acceleration, which is superior between a first fuel consumption reduction effect by inertial traveling and a second fuel consumption reduction effect by deceleration energy regeneration, the inertial traveling making the vehicle travel, with power transmission disconnected between an engine and a drive wheel (6a, 6b) of the vehicle, and the deceleration energy regeneration inputting rotational power of the drive wheel (6a, 6b) of the vehicle to an electric motor; performing inertial traveling when it is predicted that the first fuel consumption reduction effect by inertial traveling is superior to the second fuel consumption reduction effect by deceleration energy regeneration; and performing deceleration energy regeneration when it is predicted that the first fuel consumption reduction effect by inertial traveling is not superior to the second fuel consumption reduction effect by deceleration energy regeneration, characterized in that the vehicle traveling control method further comprises: detecting a speed (Vv) of the vehicle upon determining that the driver has no intention for acceleration; wherein it is predicted, when the speed (Vv) is equal to or higher than a speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is superior to the second fuel consumption reduction effect by deceleration energy regeneration, and when the speed (Vv) is less than the speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is not superior to the second fuel consumption reduction effect by deceleration energy regeneration. detecting a speed (Vv) of the vehicle upon determining that the driver has no intention for acceleration; wherein it is predicted, when the speed (Vv) is equal to or higher than a speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is superior to the second fuel consumption reduction effect by deceleration energy regeneration, and when the speed (Vv) is less than the speed threshold (Vt), that the first fuel consumption reduction effect by inertial traveling is not superior to the second fuel consumption reduction effect by deceleration energy regeneration.