Mobile payment system is gaining increasing acceptance as a mode of payment in the current economic environment. With the growing popularity of mobile payments, it is important to identify the key factors that motivate people use mobile payment. Pinpointing such factors would allow businesses to build the right mobile payment for customer’s needs. This article relies on a novel integrated model and a qualitative method to answer the question "what are the key factors influencing Mobile Payment Adoption in Hong Kong, a global metropolis where mobile payment is making steady inroads”. This study use a quantitative approach with a sample size of 203 to investigate the Influence of eight factors on Behavioural Intention to use mobile payment. The results show that factors relating to “Hedonic Motivation”, “Habit”, “Perceived Usefulness”, “Perceived Ease of Use”, “Social Influence” and “Government Support” significantly affect the Behavioural Intention to use mobile payments to conduct online transactions, while “Perceived Risk” and “Perceived Cost”  shows no significant effect. Although the TAM/UTAUT model has been extensively studied in the previous research on mobile payment services, little effort has been done to combine and investigate other influencing factors in order to test their effects on the intention to adopt mobile payment. As a result of this, this study contributed by developing and testing a novel integrated model providing a valuable guideline to help researchers looking into issues related to mobile payment services in Hong Kong.