The main purpose of this study is to measure and explore the dimensionality of the event image by using the case of 2010 Shanghai World Expo. After literature review, this study used Keller’s framework of brand image as the conceptual base, followed the free associations method to identify the preliminary items, adopted expert opinions to further revise the items, used the exploratory factor analysis to explore the underlying structure of the event image, and adopted the confirmatory factor analysis to further validate the measurement scale. Finally, five dimensions including 17 items were extracted. They are labeled as Benefit, Facility, Service, Theme, and Event Content. The results of the current study were relatively consistent with some conceptual frameworks and to some extent confirmed previous empirical studies, which could provide useful implications for both future research and industry practice.