Abstract: The study analyzed the habitat quality and space-time variation characteristics of Wuyi Mountain Reserve in Fujian Province over 30 years, which took Landsat images in 1988, 1996, 2003, 2010 and 2018 as data sources and based on the environmental assessment model of remote sensing ecological index(RSEI). The results show that RSEI index can better reflect the habitat quality and its spatio-temporal differentiation characteristics in the study area. In the model constructed in this study, the humidity characteristic vector is larger than the greenness index, indicating that the contribution rate of humidity in this evaluation model is greater than that of greenness. Within 30 years, the average value of RSEI index in the reserve decreased from 0.7064 to 0.7048, and the habitat quality decreased slightly, mainly due to the long-term heavy precipitation in 2010, mountain torrent erosion and serious damage to the habitat caused by large area mountain erosion. From 1988 to 2018, the areas with stable habitat quality accounted for 86.78%, and the areas with improved habitat quality accounted for 6.58%, and the improved areas were concentrated on both sides of the river and near the settlements, which was closely related to the establishment of protected areas and the formulation and implementation of related policies, but within 30 years, the declining areas of habitat quality were mostly distributed in the adjacent areas between the core area and the peripheral protected area. Therefore, it is necessary to delimit a buffer zone on the periphery of the core area to better protect the core area, as well as focus on monitoring and restoration of areas below the medium level of habitat quality.