The major management objective of national park is ecological resource conservation. The Yushan National Park trails attract many tourists and mountaineers, but too many users will affect recreational quality and cause environment impact. According to the recreational carrying capacity and the limits of acceptable change methods, the main purpose of this study is to evaluate the best recreational carrying capacity of hiking trails in Yushan National Park. The after-the-fact analysis was used to seek the relationships between impact parameters and management parameters. Plant coverage was selected as a key indicator for measuring limit of acceptable change. The visitors were requested to indicate their LAC for different levels of plant coverage for trails. The visitors and climbers to Yushan National Park were sampled and interviewed. The results show that the limit of acceptable plant cover reduction by the side of trails is under 40% in hiking trails, and under 40% in recreational area . The best recreational carrying capacity is below the number of 16962 persons per year in hiking trails, and 3290 persons per week in recreational area. This study results are expected to be helpful for tourist numbers control and ecological resource sustainable use.