Lianas are known to impact forest tree growth and regeneration. To understand interactions between lianas and trees is important not only for forest dynamics but also for forest management. In 50 subplots (10 m × 10 m) of a forest dynamics monitoring plot (50 m × 500 m) in a seasonal evergreen forest in northeastern Thailand, we censused all lianas ≥ 1 cm DBH and identified their host trees in 2018. Combining these data with tree census data in 2018 and canopy height class data (gap, building, or mature phases) in 1993 and 2018, we examined liana abundance along tree stem density or canopy height class gradient. We found that liana stem density showed no or slightly positive correlation with tree stem density, and that current liana stem density was higher in sites of treefall gaps 25 years earlier, than in closed-canopy sites at that time, while current canopy height classes showed no significant difference in liana density. These results might show possibilities that tree stem density does not explain liana abundance where trees exist densely enough for lianas to easily reach, and that old gaps rather than new gaps influence current spatial distribution of lianas.