When mobile communication has been vastly used, its particular characteristic is appreciated for the idea of mobile e-commerce (Me-commerce) in any electronic toll collection (ETC) applications. This paper establishes a new method of ETC using mobile cell phones integrating mobile communication with radio frequency (RF) communication adopting microprocessor control. A simple ETC system architecture and protocol for transactions among vehicles to toll stations to complete payment is presented. The proposed ETC contains e-transaction mechanism in hardware and software. A software flow through Internet is developed to link from toll station roadside units to car units. A car unit for vehicle, a pair of roadside units, and an e-Center are established. Data flow and interaction protocol are created. The proposed ETC system can be applied to toll different systems on freeways, bridges, parking lots for un-manned operation. The proposed system is designed with hardware circuit using microprocessors to match with software system. The preliminary test results on system performance verifies as a good solution for ETC applications. Some feasibility analysis is made with test support. The function capability for Me-commerce is also demonstrated.