Abstract: In the light of the characteristics of hydro-projects like high investment, long construction period, and involving a wide range of stakeholders, the credit evaluation index system of market entities in hydro-project construction are discussed in terms of thoughts and principle of establishment, structure of the index system, evaluation content and index weight so as to better serve the construction of hydro-projects and standardize the market. Based on systematic analysis and integration of factors affecting the credit of market entities, a credit evaluation index system composed of five first-grade indexes including comprehensive quality, financial circumstances, management level, market behavior and credit record, and several second and third grade indexes is put forward, and the specific connotations and weights of each index are expounded. The index system, as a useful exploration for scientific and orderly credit evaluation, can comprehensively and objectively reflect the credit of market entities in hydro-project construction.