Abstract:In order to understand the effect of host diversity and functional traits on host specificity of mistletoe, the mistletoe and host species as well as the degree of host specificity of mistletoe in Xishuangbanna Tropical Botanical Garden were investigated. The results showed that there were 1 323 host individuals, belonging to 58 families 190 genera and 286 species, infected by 6 mistletoe species and 1 variety, belonging to 2 families 5 genera. There was significant difference (P<0.01) in infection density among different habitats, which was the highest in monoculture plantation, and the lowest in forest. The degree of host specificity (H') of seven mistletoe species ranged from 1.92 to 7.05. According to redundancy analysis, the DBH, bark water content and bark roughness of host species were significantly correlated with the distribution of mistletoe on host species, whereas wood density and bark pH had not significant correlation. In conclusion, mistletoe species showed great difference in host specificity in tropical plant community, which could partly explained by the preference on specific host functional traits of mistletoe species.