Wireless transmission system and method of realizing the vehicle mounted positioning information are disclosed, said system contains: the vehicle mounted terminal equipped with RS232 port, monitoring center server, positioning information reception module which is used to receive the, satellite positioning information of vehicle, level conversion circuit which is used to convert the TTL level signal output from the positioning information reception module to RS232 signal; wireless communication module connected with the vehicle mounted terminal. Said method contains following steps: the monitoring center server of the vehicle mounted terminal and the grid points of the traffic information are started, the registration message is transferred from the wireless communication module to the monitoring center server; the satellite positioning information is received and transferred to the vehicle mounted terminal via the level conversion circuit, and packed via program to data packet for the monitoring center server by the vehicle mounted terminal. The advantages of the method are based on the network of Internet; free of investment of networking, charging is according to the communication flux, the expense is cheap, the transmission rate is fast and the reliability is high.