Lianas feature prominently in tropical forest ecosystems and yet information on\r\ntheir species composition and dominance as well as the patterns of liana-host interactions is scanty. The present study determined liana species composition dominance and host interactions in thirty 40 m × 40 m plots established in primary (15 plots) and secondary (15 plots) forests within the Penang National Park Malaysia. Lianas of diameter = 2 cm were enumerated together with their hosts (dbh = 10 cm) in the plots. Differences in liana species composition between the two forest types were determined by non-metric multidimensional scaling (NMDS) analysis analysis of similarity (ANOSIM) and similarity of percentages (SIMPER). The patterns of species co-occurrence and nestedness were determined respectively by using c-score and NODF (a nestedness metric based on overlap and decreasing fill). The various composition analyses (NMDS and ANOSIM) indicated that liana species composition differed significantly between the two forest types. Furthermore SIMPER revealed that only five liana species accounted for the top 50 % of the variation in species composition between the forests. The dominance of some liana species differed with respect to the primary and secondary forests resulting in distinct group of liana species forming the most dominant liana flora in each forest type. Liana species showed negative co-occurrence pattern in the primary forest while random co-occurrence pattern was observed in the secondary forest. The findings further indicated that there was no significant nestedness among liana communities in the two forest types.