To provide a traveling control device of vehicle so as to prohibit a return to a constant speed traveling control when specified conditions under which a return to a set vehicle speed is not appropriate are satisfied.

A vehicle speed is detected by a vehicle speed sensor 10, a distance between a vehicle and a preceding vehicle is detected by a radar sensor 26, and the detected data are input into a calculation device 14. Also a set speed for constant speed traveling control and a set vehicle-to-vehicle distance for follow-up traveling control are input from a set switch 12. Then, based on the road information obtained from a map database 28 and the vehicle positional information obtained from a navigation device 30 in the constant speed traveling or follow-up traveling, for example, when a vehicle enters into the ramp way of a highway, the calculation device 14 cancels the constant speed traveling control if it is not considered appropriate to maintain the constant speed traveling control or change over from the follow-up traveling control to the constant speed traveling control.