The risk analysis system of regional debris flow hazards is briefly discussed;and some mistakes on the study of hazards analysis of regional debris flow and difficulties on the assessment of social economic vulnerability are indicated.By means of the conception of “hazard entropy”

a new approach for quantitative risk analysis of regional debris flow hazards is brought forward.A risk assessment matrix is built up through grading the hazards of regional debris flow and the social economic vulnerability.On the basis of risk assessment matrix

the risk of regional debris flow is graded;and it will lay a solid foundation for effectively early-warning of regional debris flow and reducing and preventing hazards.