China has been by far the fastest growing source market in recent years, and now is the biggest tourism source market in the world. Mainland Chinese travellers were permitted to directly visit Taiwan in 2008. Within a short period of time, the Mainland Chinese travel market has become the top source market for Taiwan’s tourism industry. However, limited attention has been paid to the travel behaviour of this significant market, such as why and why not Mainland Chinese travellers visit Taiwan. Using interviews, this study identified a list of motivation factors and travel constraint factors. Three themes, intrapersonal, interpersonal, and contextual factors, influenced Mainland Chinese tourists’ intention to visit Taiwan. Particularly, contextual factors, such as ‘the cross-strait relations’ between Mainland China and Taiwan, play a key role in influencing tourists’ visit intention. Like two sides of the same coin, ‘the cross-strait relations’ could be the facilitator to attract Mainland Chinese tourists or the inhibitor to stop Mainland Chinese visiting Taiwan.