The perforation plates of vessel elements in secondary xylem of Liriodendron which include 2 species were observed in detail by scanning electron microscope (SEM), and many details were observed that were not reported by light microscope. Reticulatescalariform perforation plates exist in Liriodendron, and the simple perforation plate, epledroidforation and pit membrane remnants were observed in L. tulipifera. The results showed: (1) for Liriodendron chinense (Hemsl.) Sarg., the perforation plates are typically scalariform with a few bars and reticulatescalariform perforation plates, but occasionally are reticulate perforation plate; (2) for Liriodendron tulipifera, the perforation plates are scalariform perforation plates and reticulatescalariform perforation plates, but occasionally are simple perforation plates; (3) part of scalariform perforation plates in L. tulipifera with wider and more bars; (4) perforation plates with a few bars are more in L. chinense than in L. tulipifera; (5) the perforated plates in L. tulipifera are more inclined than in L. chinense; (6) epledroidforation and pit membrane remnants were observed in L. tulipifera. The conclusion is that the perforation differentiation of L. tulipifera is more violent.