In Intelligent Transport System (ITS) there is a new kind of ad hoc network: Vehicular Ad-hoc Networks (VANET). In VANET, vehicles get useful information by communicating with each other or with a roadside unit. The location information is important in VANET. It is easy to obtain the locations of vehicle by GPS technology. However, there still are some unexpected problems such as not always being in signal coverage or not being strong enough for some applications. It is necessary to develop additional localization techniques to overcome GPS limitations. In this paper, we discuss localization techniques via V2V and V2R communications in VANET when there is no available GPS information, design a dynamic positioning system based on IEEE802.11p and IEEE1609 standards, and simulate positioning algorithms of DV-Hop, RSSI and MDS-MAP.