A lossless handover method in vehicular wireless networks is disclosed which is capable of reducing a handover delay and reducing overhead caused by duplicate address detection (DAD) for a new Care-of-Address (CoA) by dividing a handover process into handover at road-sections and handover at intersections. In the handover method, a vehicle continues to use an original CoA configured at an original access router at road-sections even though an AR is changed, thereby reducing a handover delay. A new CoA is configured only at intersections to reduce a binding update time of a home agent which is remotely present in an external network at road-sections. When performing the DAD for a new CoA at intersections, since the vehicle performs the DAD as a background process while performing communication using an original CoA, overhead caused by the DAD can be reduced.