With the development of the information and communication technology and the wide use of the Internet, e-commerce has made unprecedented progress, and it gradually becomes a significant and new-developin g industry in China. E-commerce is currently experiencing huge growth. It is estimated that e-commerce in China will be worth US$ 540 billion by 2015, and by 2020 worth more than in the U.S., the UK, Japan, Germany and France combined[1]. E-commerce has made a great influence on traditional industries. Many traditional companies have achieved great success with the help of e-commerce[2]. At the same time, the social media with the centre of interaction has made a great progress, which leads the e-commerce market to change. China's economic rise coinciding with the dawn of the information age means that its consumers are web savvy and thus increasingly go online to purchase. Furthermore, Chinese consumer trust in online shops is stronger than previously imagined and they are more willing to buy luxury items online. As we know, it is one of the fastest growing e-commerce sectors in the world with highly mobile payment systems and the most rapid 4G network expansion to any country. China's Ministry of Agriculture estimates that online transactions for farm products were valued at over 100 billion RMB ($16.1 billion) last year. Many experts believe that there's still plenty of growth room. E-commerce accounts for only 3% of the total agriculture trades in the country, which is perhaps why is becoming a hotly contested battle field for internet companies[3]. Especially the agricultural e-commerce represented by tea market is booming. Many experts believe that social media play a more and more important role in electronic commerce. So it is necessary for the tea operators to spread tea culture and build the brand loyalty by using social media. This research focuses on Caihua Maojian tea which is a local brand in Hubei Province. Under the developing situation of agricultural e-commerce, we will discuss how to use social media to help Caihua Maojian tea to make great progress in marketing and brand building.