To provide a rollover prevention device of a vehicle capable of coping with a danger of rollover with time to spare for avoidance of the rollover by determining existence of the danger of the rollover of the vehicle before entering a curve, an intersection, etc. in accordance with a travelling position of the vehicle and warning a driver.

A rolling angle of the vehicle is detected by a rolling angle computing part 7, a loading state of the vehicle is computed by a loading state estimation part 8 by inputting this detected rolling angle, a driving state signal of an engine, travelling speed of the vehicle and lateral acceleration generated in the middle of travelling of the vehicle, safety passing speed at the time of travelling at a specified position is computed by a safety passing car speed computing part 9 by inputting a data of this computed loading state, a positional signal on a travelling route of the vehicle and a data of a radius of curvature of a curved road at the specified position on the travelling route, the existence of the danger of the vehicle rollover at the time of travelling is determined by a rollover danger determining part 10 by inputting each of the data found as above, and the driver is warned by warning generating means 12, 14 at the time when it is determined that the danger of the vehicle rollover exists.