The purpose of this study is to explore the dimensions of domestic tourists' decision-making styles and their roles in tourists' vacation intentions. A total of 399 Taichung residents are intercepted by using convenience sampling. The results of both exploratory factor analysis and confirmatory factor analysis indicate that domestic tourists' decision-making styles consist of four distinct dimensions, labeling careful consideration, hedonic, share/association, passive planning, and focused strategy. The four dimensions demonstrate satisfactory model fits, reliabilities, and validities. These findings suggest that the nature of tourists' decision-making styles is multifaceted and different marketing strategies should be conducted based on various tourists' vacation decision-making styles.