本文之目的在探討多時期情況下之資產替代－企業轉移借款於風險較大之投資計劃－問題。資產替代曾用於解釋資本結構，多種債務契約條款，可分散風險之風險防禦，以及存款保險之保費規劃等等。運用序列均衡之觀念，本文証明了企業信譽在重複借貸均衡關係中解決資產替代問題的角色，並探討其中利率的本質。適當使用信用紀錄，可降低資產替代問題衍生之代理成本。同時，文獻中一些依據資產替代問題所作之解釋，需要進一步的驗證。

The purpose of this paper is to study the asset substitution problem in a credit market with repeated borrowing. In literature this agency problem between the borrower and the lender has been used to explain various financial phenomena. Applying the con-cept of sequential equilibrium, this study demonstrates that the role of reputation in a credit market can deal with the asset substitution problem without contracting cost. The nature of the equilibrium interest rate is explored and the welfare implication is dis-cussed. Since the agency costs can be reduced in this equilibrium, the explanations based on asset substitution argument need to be examined more carefully.