The prosperous development of the Internet gives a large area of improvement to the traditional monitoring systems which use leased lines as the transmission media. As confined by the leased line, the old system can be accessed only at the remote site of the line. Thus the old system is lack of mobility. Moreover, the leased lines are expensive compared to subscribing the access for the Internet. In this paper we focus on the feasibility of replacing the legacy leased lines with TCP/IP connections for the communication media to build a remote supervision and control system. By this way, the system is more flexible as the operators can get access to monitor and control the system from anywhere and at anytime. Since most of the existing systems are connected to the computer with the legacy RS-232 interface and the recently produced PCs have no such interface equipped, the popular USB interface has to be considered. This study includes the process of evaluation, data collection, experiment, editing, revision, debugging, on-line test, and on-line operation to construct an web-based remote control system that carries both RS-232 and USB interfaces. We believe that with the USB equipped, the system will be more practical and valuable. Since the Internet is an open system, it is under the threats of hacking and computer virus all the time. Therefore, security is a critical issue. In our system, a firewall system and an intrusion detection and prevention one will be installed to ensure the security.