摘 要 近年来，我国电子商务进入快速发展的轨道，交易额以年均35%的速度快速增长，其中，B2C电商平台的发展速度尤为明显。随着B2C电商平台的市场格局的日渐明朗，与此同时也暴露出其发展的部分问题，如普遍黏度不足等。目前，电商平台企业间的竞争已不再是个体之间的竞争，而是新的商业生态系统间的对抗。因此，明确B2C电商平台网络外部性的影响因素，进而提出充分发挥网络外部性的发展对策，对于B2C电商平台及其中的企业来说具有重要的意义。本文的主要研究工作如下： 在现有文献的基础上，综合考虑电商平台市场、网络外部性等相关研究成果，较为严谨的界定了B2C电商平台的网络外部性的内涵，即在一定的网络基础条件下，两组或者多组电子商务卖家和买家作为参与者通过网络平台进行交易，但市场参与者不能把网络效应内化，即网络效应不能通过价格机制进入收益或成本函数的时候，使用者从用户网络中获得的额外福利变化；基于我国目前B2C电商平台的发展现状、特点及问题，分析了B2C电商平台直接和间接网络外部性关系，指出买卖双边影响的作用是相互交融而复杂的，两者直接的作用会推动网络外部性的发生；进一步的，构建了B2C电商平台网络外部性的分析架构，发现B2C电商平台网络外部性受到买卖双方、买方与买方、卖方与卖方的市场中多种因素的影响；选择相关指标，对B2C电商平台网络外部性进行统计分析，发现店铺创立时间、累计历史销量、产品被收藏次数对B2C电商平台的网络外部性有显著的促进作用，这就要求企业要通过精细化运营，提供具有特色化的产品。通过对指标的回归分析，发现创店时间、产品被收藏次数与B2C电商平台网络外部性有显著的影响，说明厂商应通过店面建立起买卖双方、卖卖双方之间具有网络外部性的相互关系，准确把握消费者需求变化，提高对网络外部性的应用。本文通过实证分析明确制约B2C电商平台价值实现的网络外部性因素，有利于平台在瞬息万变的现实竞争中，针对短板或瓶颈采取相应对策，以解决电商平台运营中的问题，以真正提高平台黏性，获得持续竞争优势。

ABSTRACT With the rapid development of Internet and the economic society, the development of electronic commerce in China can be said to have entered a fast track. According to statistics，China's e-commerce transaction volume is growing at an annual rate of 35%, of which, the development of B2C business platform is particularly obvious. Although B2C platform meets many problems in its development process, such as the price war，and the contradiction between the supplier and the B2C electric platform events such as break out frequently, B2C business platform industry market structure is becoming clear. Therefore, making sure of the influence factors of network externality of B2C platform, and putting forward develop countermeasure of network externality will play an important role for the enterprises in B2C platform. This paper shows the following results. Based on the present research of network externality of B2C platform, the paper defines the connotation of network externality of B2C platform: under the condition of certain network foundation, two or more e-commerce electricity carry on transactions in B2C platform, but they can’t achieve network effect among themselves and network effect can works well with price mechanism or cost function, the user can receive additional benefits from the network; based on the development present situation, characteristics and problems of B2C platform, this paper analysis the direct and indirect network externalities of B2C platform, and puts forward that the interaction between buying and selling of bilateral is mutual and complicated. Farther more, the paper establishes the analysis framework of network externalities of B2C platform, such as buyers and sellers market relationship, buyers and buyers market relationship, sellers and sellers market relationship; the paper selects built-up time, product price and other factors to establish the evaluation index system of the network externality of B2C platform. With the statistic analysis, the paper finds that built-up time, cumulative history sales, collection times have a great influence on the network externality of B2C platform, and this is to say that the enterprises should take refinement operations to make specific product. With the analysis of regression, the paper finds that built-up time and collection times have a great influence on the network externality of B2C platform, and this explains that the enterprises should establish the mutual relation between buyers and sellers with network externality of B2C platform, and grasp the consumer demand change precisely to improve the application of network externality of B2C platform. With the empirical analysis, this paper makes sure of the influence factors of network externality of B2C platform, which is quiet important for the companies in the B2C platform to find out the homologous countermeasure to overcome the problems in operating. And this will lead to more consumption of viscous of B2C platform, and obtain the sustainable competitive advantage.