The causes and characteristics of short interruption and its impact on customers are analyzed. The implication of short interruption is described and suggestions on the definition of short interruption in China are proposed. Through questionnaire and customers interview， an investigation is conducted on the distribution network short interruption situation and relevant customers short interruption cost in a coastal city. An appraisal method for customers short interruption cost is proposed. The relationship between the customer cost and the duration of short interruption is dealt with and the characteristics of customers short interruption cost are indicated.