Aiming at the urge demand of a large amount of real-time data transmit in industry and academy fields, the authors analyze the advantages and disadvantages of many kinds of present protocols, take advantage of UDP protocol and standard 802.4 of Token Bus. The real-time network protocol is presented based on UDP protocol and virtual token. And this paper illuminates the principle of real-time quality and reliability about the protocol, giving the frame format of the protocol and the format of Virtual Token. It demonstrates the capability of the protocol with a point-to-point transmit example that constructed according to this protocol.