We draw theoretical support from the concept of customer participation and cognitive dissonance theory to investigate the moderating effects of the preference-related belief of nature-based tourists, that is, the New Environmental Paradigm (NEP), on relationships between tourist experiential components and outcomes. The responses of 500 visitors to the Yangmingshan National Park, Taiwan indicate that actively participative experiences (APEs)-that is, education and escapism-are more positively related than passively participative experiences (PPEs)-that is, entertainment and esthetics-to pleasure and memorability. Furthermore, tourists' NEP appears to reinforce the effects of APEs and to weaken the effects of PPEs. We also found that tourists' NEP has a stronger reinforcing effect than a weakening effect. Our study contributes further evidence to current insights into the importance of tourists' participation in co-creating value of tourist experiences.