Reducing private car use is an efficient way to promote the sustainable development of national parks. However, many visitors persist in using their cars, even when they are aware of the environmental damage it causes. This study proposed a norm-neutralization model to investigate why national park visitors persist in car-based trips by partially integrating the theory of planned behavior, the norm-activation model, and neutralization theory. The results indicated that neutralization techniques can effectively reduce the effects of social norms and attitudes on carbased trip intention in a conflicting-norm context. The strongest predictors of behavior intention were attitudes toward the behavior while neutralization techniques were the second strongest. The effect of pro-driving norms showed a significant reduction when neutralization techniques were added, but pro-environmental norms did not have a significant effect on behavior intention. Practical and theoretical implications, as well as directions for future research, are discussed. Keywords: norm-neutralization model; pro-driving norms; pro-environmental norms; neutralization techniques; car-based trip; national parks 1. Introduction Increased disposable income has boosted the growth of private car ownership and car-based trips in developing countries. By March 2017, the number of private cars in China had risen to over 150 million (China Transport Administration of Public Security Ministry, 2017). The car is becoming the main travel mode among Chinese for short-haul holiday trips. According to a report by the China Tourism Academy, there were 32.13 million car-based tourists during the eight-day super holiday for the 2017 National Day and Mid-Autumn Festival (China Tourism Academy, 2017). Private cars provide many benefits for travelers, including benefits that are functional (e.g., convenient), psychological (e.g., pleasurable), and social (e.g., self-image boosting) (Ellaway, Macintyre, Hiscock, & Kearns, 2003; Uba & Chatzidakis, 2016), thus promoting the formation of pro-driving norms. However, private car use is also a major contributor to overall carbon emissions from the transport sector (Klockner & Friedrichsmeier, 2011). Transportation dominates the energy bills of domestic and international tourists, accounting for 65-73% of total energy use (Becken, Simmons,