Disclosed is an optical line monitoring system and method which detects an optical line where a disorder occurs, by using an OTDR (Optical Time Domain Reflectometer) pulse pattern with matching information. The optical line monitoring system generates and stores a reference OTDR pulse pattern matched with identification information of an optical channel service unit, and compares the matched reference OTDR pulse pattern with the OTDR pulse pattern collected at an inspection time to verify an optical line region where a disorder occurs.