Abstract: In the face of escalating global environmental challenges, national parks, as a core component of the global system of protected areas, play a crucial role in maintaining ecosystem sustainability. This study reviews the evolution of the legal framework governing national parks worldwide from the perspective of ecological conservation, and examined changes in value goals, legal concepts, governance structures, and accountability mechanisms. The findings indicate that national parks have evolved from initially focusing on landscape appreciation and public recreation to governance models centered on ecological integrity, ecosystem services, and holistic protection of natural-cultural heritage. Despite differences in legislative traditions and management arrangements among countries, the principles of "prioritizing ecological conservation, public participation, and multi-stakeholder collaboration" has become a common foundation of the national park legal system. The study further identifies climate change, human activity disruptions, funding shortages, and the complexities of cross-border governance as key institutional bottlenecks that limit ecological conservation effectiveness. The existing legal frameworks remain inadequate in addressing rapid environmental changes, enhancing ecological resilience, or reconciling diverse societal demands. In many countries, climate adaptation has not been fully integrated into statutory mandates, leading to fragmented responses and limited management guidance. Human activities, including local interest competition and economically driven pressure groups, can undermine ecological priorities and distort governance outcomes. Funding constraints hinder essential ecological functions such as long-term monitoring, habitat restoration, and law enforcement, increasing the risk of management priorities shifting towards tourism-oriented goals that are misaligned with ecological conservation. Additionally, cross-border national parks face challenges due to inconsistent legal standards, uneven enforcement, and competing national priorities, hindering coherent ecosystem-scale conservation. To address these challenges, the national park legal system must strengthen climate adaptation provisions, incorporate ecological resilience into statutory objectives, and enhance the scientific rigor of public participation. Multi-stakeholder collaboration should be supported through clearer rights and responsibilities and equitable benefit-sharing mechanisms to foster community involvement. Stable and long-term financial resources (through dedicated funds, diversified financing tools, and performance-based allocations) are critical for maintaining core ecological conservation tasks. For transboundary national parks, international agreements should delineate management responsibilities, promote information sharing, and achieve coordinated enforcement to overcome legal fragmentation. Modern technologies such as remote sensing, drone systems, and GIS can further support adaptive management and global ecological data integration. Overall, the improvement and strengthening of legal accountability, oversight mechanisms, and procedural safeguards is vital to ensuring the effective implementation of ecological conservation rules. By strengthening the legal framework, stakeholder cooperation and international coordination, national parks can more effectively fulfill their roles in global ecological conservation and sustainable development.