After analyzed the requirement of EPON (Ethernet Passive Optical Network) cable online monitoring system and the shortcoming of the present monitoring methods, a new software of B/S (browser/server)and MVC(Model View Controller) structure is proposed for EPON cable online monitoring. The designed EPON online monitoring system is implemented through Web-based central structure. This EPON cable online monitoring system is capable of monitoring the multiple lines in parallel and timely detecting the faults. The efficiency of monitoring is enhanced. In addition, the system can locate the fault by GPS as soon as the failure occurs. The warning that is created automatically is sent to the maintainer by email and short message. Compared with the present maintenance system, the presented software system reduces the complex manual operations and shortens the time of out of work in the EPON network. The operation of our software will improve the EPON network management level tremendously.