In this thesis, an error repairing scheme for LR(1)-based parsers, whose repair action is based on insertion, is studied. This error repairing scheme consists of two parts. One is an Error Repair Table which is automatically generated in paser generating time. Another is an error repair routine which operates at encountering syntax errors. For construction of the Error Repair Table, the existing parser generating system is modified and extended. This error repairing scheme has been implemented on IBM 370/145 UM/CMS system and tested with XPL language.