一、企业竞争力量的结构与变化根据波特尔（PORTER）的竞争理论，企业面对环境中的五种竞争力量：供应者、消费者、现实竞争者、潜在竞争者和替代竞争者。驾驭企业与五种竞争力量的关系是企业竞争战略的重要课题。处于改革开放环境中的中国企业还面对着另一种重要的竞争力量，? I. Structure and Change of Firm Competitive Power According to PORTER's competitive theory, enterprises face five kinds of competitive forces in the environment: suppliers, consumers, actual competitors, potential competitors and alternative competitors. Managing the relationship between the five competitive forces and enterprises is an important issue in the competitive strategy of enterprises. Chinese enterprises in an environment of reform and opening up also face another important competitive force?