1.Radial cracks of the Larch woods usually run along the tissues of wood ray. Ring cracks mostly occur in the boundaries between earlywood and latewood and of the zones with the wide and narrow growth rings,within the latewood zones,and along the boundaries of the growth rings where the wounded parenchyma is located.The cracks of latewood have frequently been found in the compound middle lamella of the cell wall, but less in the outer layer of the secondary walls(Sl). 2.The shrinkage value is higher in the wood with wide growth rings than that with narrow ones,but the anisotropy coefficient is quite the reverse;similarly,it is true in comparison the zones of latewood with that of earlywood.These distinct differences in characters of shrinkage are the main factors causing the cracks of the Larch wood (particularly to ring cracks). 3.The wood rays in some extent,have restrictive effects on the radial shrinkage of Larch wood,but these effects are not the main factors causing the transverse aniso- tropic shrinkage.The more the rows of tracheid and the distance between rays are,the less are the influences. 4.The thickness shrinkage of the cell walls is relatively less in the radial direc- tion than that in the tangential,and also in earlywood than that in latewood.The shrinkage value in diameter of tracheids is greater in the tangential direction than in the radial direction,and also greater in latewood than in earlywood.After shrinking the diameter of the cell cavities of tracheids increases in the radial direction but decreases in the tangential direction.After shrinking the area of cell cavities in latewood increases somewhat in size but the area of cell cavities in earlywood decreases a little. 5.After shrinking of the wood the variations in the diameter of the tracheids and cell,cavities are one of the main factors causing the anisotropic shrinkage of Larch wood(particularly to earlywood).The differences in diameter shrinkage of the tracheids and cell cavities both in the radial and the tangential direction,and in early-and late- woods,are greater than those in thickness shrinkage of the cell walls. 6.The bordered pits on the radial walls of earlywood tracheids have some re- strictive effects on the radial shrinkage of earlywoods.Meanwhile,they cause the in- crease in the anisotropic shrinkage of earlywood.