With the ever-accelerating development and universal application of mobile communication technologies in China, mobile social networks are now playing a major role and are being widely utilised in the daily lives of Chinese academics. Such academics nowadays are involved in sharing their information and keeping in touch with others via social networks: in particular, WeChat or QQ. Accordingly, WeChat is now regarded as one of the most popular mobile social platforms in China with more than one billion active users all over the world by 2017. This is because of its diverse media functions, such as micro-video and voice-chat, and its ability to share texts, photos and videos. So, an increasing number of Chinese academics have become accustomed to spending time and energy on the WeChat platform with a view to maintaining and enlarging their scholarly and interpersonal relationships via this virtual social network. However, when considering social capital theory, which is based on Western thought, the Chinese people tend rather to engage in establishing and developing guanxi (a Chinese term meaning "interpersonal connections"). These are unique and pervasive interpersonal relationships based on the deep-rooted influence of Confucianism in the traditional Chinese culture. Although universities have been generally considered as knowledge-innovative and knowledge-intensive units, research into knowledge management in Chinese universities is extremely limited. Therefore, this research aims to contribute to an understanding of knowledge-sharing behaviour among academics in Chinese universities through the investigation of guanxi and the working habits that might affect them. A research model was constructed from individual cognitive, psychological and sociological factors that were considered to influence Chinese academics' knowledge-sharing behaviour and then an empirical survey of 101 sets of valid data, collected from WeChat users, was analysed using structural equation modelling to test both the measurement model and the structural model. Consequently, the theoretical and practical implications of the findings are discussed.