With the development of information technology,electronic commerce is changing the way of management in enterprise,life style of family a nd people.Under electronic commerc e,market -management,sale -manage ment and customer -relationship managem ent of enterprise is substantially d ifferent from traditional commerce.Thus,it is a key issue faced by every enterprise to study the theories and methods of E -business.The paper analyses the relation between customer -relatio nship management in traditional cir cumstances and in electronic commerce.On the basic of the analyses,it studies the strategies of customer -relationsh ip management before sale,during sa le and after sale in an enterprise.