According to World Bank statistics, internet user occupied a quarter of the world population in 2008. In 2010, the number of internet users will be over two billion people. This group will become potential online shopping customers. Online shopping in global market keeps growing. Online shopping has become a trend. The business model of E-continues is facing highly challenge in this market. Enterprises need to look for sustainable way to keep their business continuously growth. This research is based on the external analysis of online retail industry in the U.S.A and the internal analysis of the core resources of the Amazon.com to evaluate the key factors of online M&A targets, to adjust the strategy in highly competitive industry, to utilize the resources acquired by Amazon.com to build up competitive advantage and to implement the effectiveness of strategy. The study mainly research 13 companies acquired by Amazon.com from 2008 to April 2011 on the relationship between core resources and competitive advantage. The study concludes that M&A motivation of Amazon.com is to extend product line, to enter new markets, to obtain the necessary resources and capabilities, to expand the operation scale of the industry. According to the findings and conclusions, the suggestions of the study as followed. 1. In Chinese digital content industry: firms should be focus on content development to build up the competitive advantage of digital content platform. Meanwhile the digital content can be used in each e-reader. In addition, the firms can cooperate with telecommunications firms to provide added-value service. 2. The study found that many internet companies differentiate customer service and build trust from customer by online services to create competitive advantage like creating user community to share knowledge and resources; using word of mouth marketing to attract new customers. Executives should focus on their customer-orientated service to meet market demand.