Abstract: A vehicular real-time information query mode based on vehicular Ad hoc network (VANET) is proposed in this paper. The real-time traffic information report, facilities service information report, user queries, etc., are disseminated via epidemic routing in the system. Only after a query and a report matched at a node, the report will be returned to the query node via infrastructure network to speed up the query efficiency. The system model is analyzed and the system delay is theoretically deduced. Furthermore, the derived conclusions are validated in STRAW/SWANS simulator, which provide a theoretical basis for parameters setting and optimization for the VANET system.