Abstract
This study analyzed survey data from 442 environmental NPOs to examine organizational characteristics and the challenges of securing human and financial resources. Many organizations faced personnel shortages and fragile financial bases, with succession problems particularly severe among small-scale groups and those led by older representatives. In contrast, successful organizations typically had larger budgets and tended to engage in SDG-related or network-based activities. Regression analysis revealed that securing financial foundations, ensuring successors, institutional support, and fostering citizens’ sense of personal responsibility for environmental issues were all essential for organizational development, and reinforcing both internal and external foundations was important. Given that internal challenges do not necessarily align with the promotion of citizen participation, mechanisms connecting the two are required.