Employee is an important factor which has strong influence on the success of Business Process Reengineering (BPR).In order to analyze employees in BPR fully,this paper imports the principalagent theory into BPR.By using this theory,this paper analyzes principals and agents existing in BPR and the relationship between them.First,it analyzes the relationship between the principal-agent theory and BPR to validate the possibility of applying principal-agent theory to BPR; secondly,under the analysis framework of the principal-agent theory,it specifically analyzes the principal-agent relationship in BPR and establishes the two-stage model for BPR based on the principal-agent theory.At last,it improves the model established and provides algorithm and relative explanations.