WeChat payment has recently become a popular mobile payment service in China by bundling with WeChat, the most popular social network service in China. It is interesting to investigate the reasons for its popularity. In this research, we applied the technology acceptance model to predict its acceptability and to identify variables attributing to its popularity. In addition to the primary explanatory variables, i.e., Perceived Ease of Use and Perceived Usefulness, the proposed framework is further extended to include the constructs of Social Interaction, Trust, Perceived Enjoyment and Use Context. The results indicated that the proposed model is able to explain the variance in a user's intention to use WeChat payment service. We hope this study can provide insights into understanding the adoption behaviour of socially aware mobile payment services.With the development of information technology, E-commerce has become an important part of modern economic industries and a magnificent growth has been observed in recent years. Many companies added E-commerce models to their operations and began innovative marketing and sales programmes via the Internet [3]. Moreover, handling financial transactions over the Internet has also greatly changed people's lifestyle, especially in the payment field.Currently, online mobile payment has become one of the most important smartphone services in E-commerce [41], since mobile payments can lead to customer satisfaction [41], cost reduction [67], competitive advantage [25] and firm growth [71]. Mobile payment enables users to check account balances, transfer money, pay bills and conduct financial management at any time from anywhere [43]. Due to the advances of mobile Internet technology, and the rapid growth in the number of mobile users, making payments for goods, services, and bills via mobile devices is now playing an increasingly important role in our daily life [54]. For example, according to the data of the recently released report, The First Quarter of 2017 China's Third Party Mobile Payment Market Monitoring Report, China's third-party mobile payment market size of 18.80912 trillion yuan increased 46.78% [61].Although Alipay is maintaining the largest mobile payment platform in the China, WeChat payment's market share has grown from 10% to 40% in the past three years, and it is close to that of Alipay. Tencent released WeChat payment in 2013 and bundled it with WeChat 5.0 so that users could simply click on the item links in the chat window to easily complete payments [8]. Moreover, through the red envelope promotion, WeChat payment attracted more than 8 million users, giving away 3 billion RMB on Chinese New Year's Eve in 2014 [9]. In 2017, the total number of WeChat red envelopes sent and received was 46 billion, up 43.3% from the previous year [60].Compared with Alipay, WeChat payment is obviously different due to its social factors. WeChat is currently the most popular mobile social network service application in China. Its number of monthly active users has increased to ...