A comparative study on secondary xylem structure among three species in Liriodendron (Liriodendron chinensis, L. tulipifera and L. chinensis×tulipifera) was carried out. Average number of bars in scalariform perforation, the length of vessel elements, the number of length and width of ray tissue and the cell number of parenchyma strands were significantly different among three species. The most features of secondary xylem structure of L. chinensis×tulipifera were between two natural species. We first found about 4% vessel element with simple perforation in L. chinensis. Compared with L.chinensis, there were more evolutional features in L. chinensis including shorter vessel member length, less number of bars presented on scalariform perforation, less ray length and width and cell number in parenchyma strands.