Abstract: The purpose of this paper is to illustrate some research results on quantitative analysis of wood and tomical elements of two Poplar species (Populus pseudo-simonii and P.X xiaozhuanica). The measurements are made with an automatic image analyser on microscopic transverse sections of the stem of some 18 years old trees.The proportions of the various tissues in growth rings and the dimensions of vessels,fibers and rays,etc.are tabulated.The difference in the proportion of the rays in these two poplar species is not significant. But in P.X xiaozhuanica the proportion of vessele lumen areas is larger than that of cell walls of vesseles and its fiber is smaller then the other one.