Abstract: A fault monitoring system and fault reporting method therefore that monitor faults in a transmission system and notify a monitoring unit including maintenance personnel, a monitoring device, etc. have a fault detection unit that detects occurrence of faults and release of faults of units in a transmission system, and a fault history information generation logic unit 2 that adds one-bit fault history information to a software counter unit based on the fault occurrence information or fault release information from the fault detection unit, the presence of any change for each software reading timing, and the previous-time output information.