Strong subjectivity, redundancy, without valid instauration grounds are the main characters of present risk indices
of enterprise resource planning(ERP) system implementation. Based on attribute reduction method in rough set theory
and an investigation of fifteen enterprises who has completed ERP system implementation, risk controlling attributes of the
implementation process are reduced. The results show that the usage of attribute reduction theory in such area is effective, and
seven important risk indices are obtained, including human resource management, enterprise modeling, project management,
and so on.