Abstract: National Park of Hainan Tropical Rainforest is one of the first national parks established in China. Scientific and rational transportation planning is a powerful guarantee for ecotourism, environmental education and community development in national parks. Focusing on the highway transportation routes from Haikou and Sanya cities to the main towns or areas within National Park of Hainan Tropical Rainforest, this study quantifies the transportation accessibility of the main towns or areas within the park using ArcGIS 10.8. The main results are as follows: The average travel times from Sanya to the main towns and areas within National Park of Hainan Tropical Rainforest are all significantly shorter than those from Haikou; the towns with higher highway transportation accessibility coefficients within the park are primarily distributed on both sides of the highways; shorter average travel times and lower accessibility coefficients indicate more convenient transportation. The highway transportation accessibility coefficient varies among areas within the national park. Yinggeling, Wuzhishan, Maorui, and Limushan areas exhibit accessibility coefficients less than 1, indicating better transportation accessibility compared to Jianfengling, Diaoluoshan, and Bawangling areas. The results of this study can provide reference and basic data for road planning in National Park of Hainan Tropical Rainforest.