Lianas are abundant in tropical rainforest. With global climate change, liana density and biomass are increasing. This can significantly influence co-occurring tree recruitment, growth, mortality and survival, which, in turn, may have a significant effect on the structure, functioning and dynamics of tropical forests. In this study, we measured 17 leaf traits of 20 tropical rainforest liana species from 13 families and analyzed trait associations across lianas. Our results showed that relative water content of liana leaves exhibited the smallest interspecific variation, with a coefficient of variation (CV) of 5%, adaxial epidermis thickness presented the largest interspecific variation (CV of 80%), with the CV of the other 15 traits ranging from 24% to 61%. Across the lianas studied, both vein density and leaf density were positively correlated with stomatal density; and, specific leaf area was negatively correlated with leaf dry matter content. Compared with trees growing in the same habitats, lianas had lower values for leaf area, stomatal density and leaf density, but higher specific leaf area, with no significant differences in leaf anatomical traits between lianas and trees. These results are essential for understanding the ecological adaptation of lianas in tropical rainforest.