Abstract: This investigation focused on the antecedents and impacts on volunteer pro-environmental behavior, and explored the effects of meaningfulness through pride and environmental passion according to the cognitive appraisal theory of emotions. A mixed method research design was used, consisting of interviews, observations, and surveys with volunteers. The research was conducted at Danxia Mountain in Guangdong Province, China, a protected area, UNESCO World Heritage List site, and Geopark. Based on a survey of 302 volunteers, a sequential mediating model was tested through bootstrapping. It was found that perceived volunteering meaningfulness improved sustainable pro-environmental behavior, and pride and environmental passion played sequential mediating roles between meaningfulness and pro-environmental behavior. Compared with pride, environmental passion was the more significant and proximal antecedent of pro-environmental behavior. In addition, awe of the place strengthened the effects of pride and environmental passion on pro-environmental behavior. Theoretical and managerial implications for sustainable development practices in protected areas are outlined.