The evolution of different kinds of vessel molecules is always related to plant evolution. Ranunculaceae(Ranunculales)is a key family which links the basal angiosperm and the core-eudicots in the angiosperm phylogeny group system. Studies on the vessel perforation plates of this important family have great systematic significance, but few studies have been addressed till now. Here, the vessel elements and their perforation plates in the secondary xylem of Ranunculeae, including seven genera and eight species, were observed with the scanning electron microscope and the semithin section, in order to know the relationship betweenthe vessel with their environments in different species in Ranunculaceae of Ranunculeae. The results were as follows: Simple perforation plates were found in seven species, except for the Batrachium bungei; Scalariform perforation plates were found in four species, i.e. Callianthemum taipaicum, Adonis sutchuenensis, Ranunculus sceleratus and Halerpestes cymbalaria, but not for Ranunculus chinensis, Oxygraphis glacialis and Ceratocephalus orthoceras; Perforation plates of vessel elements of Adonis sutchuenensis were diverse, including simple perforation plate, scalariform perforation plate, reticulate perforation plate, gnetum type perforation plate, and scalariform-reticulate perforation plate; Simple perforation plate, scalariform perforation plate, and reticulate perforation plate were found in Halerpestes cymbalaria. In this study, we did not found vessel elements by dissociation the root and stem of Batrachium bungei. On the contrary, we found that there were annular vessels by semithin section. We also found that the side walls, and the pit membranes were unbroken or residual. The length diversities of those vessel elements of Ranunculeae were very high. There were significant differences in the average length of vessel elements in different species of Ranunculeae. At the same time, the differences were conspicious among different types of vessel elements even in the same species. We also discussed the adaptive significance of different types of vessel elements and the systematic position of Ranunculeae in the family Ranuculaceae. The results indicate that micro-structures of the vessel elements are also adapted to their growing environments. The vessel elements of Callianthemum taipaicum, Adonis sutchuenensis and Oxygraphis glacialis were related to their cold environments and those of Ceratocephalus orthoceras and Batrachium bungei were related to xerophytic and aquatic environment, respectively [ABSTRACT FROM AUTHOR]