Abstract: The wood anatomical properties of 24-years-old hybrid tulip(Liriodendron chinense×L. tulipifera) trees were studied. The results show: the average number of vessels is 6 per mm2, the average diameter of vessels 57 μm,the average length of vessels 647/xm,the growth ring width 1. 72～11.93 mm, the fiber length 0.80～1.74 mm,the diameter of fiber 20.9～31.6～m,the thickness of single fiber wall 5.13～5.49μm,the ratio of fiber length to width 48.02～55.74, the ratio of double wall thickness to lumen 0. 57～0. 66, the microfibrillar angle of fiber 6.62～418.62～～The radial variationlaws of the hybrid tulip tree are as follows. The fiber length,width and ratio of fiber length to width fiber from pith to bark increase rapidly,tend to stabilization at the 9～11 year growth ring. The microfibrillar angle of fiber increases with the age of growth increment and reaches to the biggest at 7th year. The annual ring,tends to stabilization at the 11th year ring. The boundary between the juvenile and mature wood of the hybrid tulip tree is at the age of 9～11 years by the order cluster analysis to above anatomical properties. T-test indicated that there are significant differences between the anatomical properties of juvenile and mature wood.