EXECUTIVE SUMMARY Mainland Chinese is one of the most important targeted markets for the Macau tourism industry. It brings huge income to the Macau economy. Macau has at least three advantages in capturing the China market: geographical proximity, cultural heritage in the mix of Portuguese and Chinese styles and newly-built leisure facilities. The importance of China outbound tourists to Macau has drawn the interest of both scholars and businessmen in understanding what makes Mainland Chinese travel to Macau and stay longer? The literature considers the length of stay as one of the major issues that need to be resolved in a visitor’s decision-making process (Decrop & Snelders, 2004). One of the main characteristics of current tourism is the reduction in the length of stay at a destination (Alegre & Pou, 2006). In vacation decision making, visitors weigh up the benefits of different vacation alternatives, assess the cost of each alternative and the length of stay they can afford to reserve and pay for, by taking into consideration their financial and time constraints (Alegre & Pou, 2006). For this purpose, it is essential to understand what drives the Mainland Chinese to prolong the days stayed in Macau. Following up the theme mentioned above, the main goal of this research was to investigate the influence of the selected underlying motivations and constraints of the Mainland Chinese leisure tourists under the Individual Visit Scheme (in short “the tourists” below in this study) on the length of stay in Macau. Empirically, nine independent variables were identified, three were classified as push motivations, and they were (1) ‘KNOWLEDGE’ factor, (2) ‘PRESTIGE’ factor and (3) ‘ENHANCEMENT OF HUMAN RELATIONSHIP’ factor. Another three of them were noted as pull motivations, they were (4) ‘RECREATION IMAGE’ factor, (5) ‘EXPENDITURE’ factor and (6) ‘ACCESSIBILITY’ factor. The remaining variables were intrapersonal constraint (7) ‘TIME’ factor, interpersonal constraint (8) ‘PARTNER’ factor, and finally structural constraint (9) ‘FACILITY’ factor. Based on Hanqin and Lam’s (1999) push and pull motivation factors and Alexandris, Tsorbatzoudis and Grouios’s (2002) hierarchical model of leisure constraints, the model based on the above factors was adopted as a conceptual framework for the study. The results indicated that the importance of these factors in motivating and constraining the tourists to travel to Macau was different from other studies. Three hundred and twelve (N = 312) successful responses from the tourists was the sample size to participate this study. The result was summarized by SPSS software (Statistical Package for Social Science) and was analyzed by the techniques of frequencies and multiple regression. According to the research result, it showed that ‘ACCESSIBILITY’ factor, ‘RECREATION IMAGE’ factor and ‘KNOWLEDGE’ factor appeared to be the most important motivations. The regression analysis indicated that ‘ENHANCEMENT OF HUMAN RELATIONSHIP’ factor negatively affected the tourists’ length of stay in Macau. The finding also indicated that ‘PARTNER’ and ‘FACILITY’ constraints were the significant factors that constrained this group of tourists to stay in Macau longer. In conclusion, the study therefore emphasized the need for the Macau tourism industry’s participation and took this research as a reference to further strengthen 4P marketing strategies to the target segment.