As socio-economic developed, the main components of the natural protected area system in China has experienced an important transition from nature reserves to national parks. Based on multiple-streams framework, the systematic changes of natural protected area system under the background of national park development was analyzed. First, the applicability of multi-streams theory in the study on China's natural protected area was demonstrated from three aspects, namely internal logic, degree of democratization and control of multiple-variables. The key influential factors in the transition of China's nature reserve system were identified from the aspects of problem stream, policy stream and political stream. Then, the logical route of the transition were summarized, the changes were concluded as well. In which, management object, management subject and management strategies were the three main changes in the transition of China's nature reserve system, aiming to reform and solve the existing problems in China's nature reserve system. By adding the type of national park as the main component, resources in the natural protected area were integrated and optimized, which could be regarded as the change of management object. While the change of management subject was mainly explored in the establishment of a unified, standardized and efficient management system, and the National Park Administration uniformly performed the management responsibilities of national parks and other nature reserves. Changes of management strategies were to establish modern management system with multilateral participation, adhering to government leadership and multilateral participation, and highlighting the social welfare of the construction of nature reserve system. The results showed that, the transition of China's natural protected area system was an unavoidable result of cohort impacts of problem stream, policy stream and political stream. The index data and problem feedback in problem stream promoted the proposals and suggestions in policy stream, while the conflicts between focus events and governance concept in the political stream catalyzed the transition of China's natural protected area system. A gradual improvement process was found in the policy stream, and especially the trials of national park pilot played a key role in the development of policy stream. The logical route of the change was mainly affected by the interaction of the three streams. The increase of problems in the nature reserve system promoted the proposals of policy schemes and policy pilots. As the policy pilot putting forward, the technical feasibility of the policy scheme could be continuously enhanced, which laid a foundation for the progress of the national parks. By the development of national parks, China's nature reserve system is reshaped to promote its systematic, integrated and coordinated development.