Lianas (woody vines) are important components of forest ecosystems and are often found to proliferate in young forests that have experienced large-scale disturbances. However, little is known regarding the mechanisms of the spatial assembly patterns of co-occurring lianas and trees in the temperate secondary forest stands. In this study, we examined the woody plants (lianas and trees) with a stem diameter > 1 cm within a one-hectare plot on a steep mountain slope (32(degrees) average slope angle) in a temperate secondary forest in central Japan. We investigated the impact of the host trees, topography, and canopy gaps on the distribution of liana. We aimed to determine the factors that influence the spatial distribution differences between the co-occurring lianas and trees. The results were validated using the 10 m x 10 m quadrats (N = 40) distributed across 23 ha within the study site. We recorded 123 liana stems on 1536 trees belonging to 57 woody species in the one-hectare plot. The findings revealed that lianas are more abundant on larger host trees and less common in high tree density areas. Small and large lianas preferred steep and moderate slopes, respectively, whereas larger trees were primarily found on steep slopes. These variations in liana and tree distribution patterns on steep slopes, which we observed throughout their life history, may be attributed to the combined effects of varied historical anthropogenic disturbances and grazing impacts. This highlights the need to consider the diverse environmental responses of lianas and trees at the different life history stages to accurately understand liana colonization and proliferation in forests.