Abstract: This paper discusses the assessment method of coastal erosion disaster loss, and gives the calculation methods of economic loss caused by coastal erosion disaster, including economic loss of land, economic loss of vegetation, economic loss of infrastructure, cost of new-built protective protect and restoration project, loss of tourism value.The paper selects two indexes of land loss area and direct economic loss to determine the disaster degree of coastal erosion with administrative district as unit.Finally, the assessment method is used to evaluate the coastal erosion disaster loss of Dalian.