The resin canals of Tenasserim Pine (Pinus finlaysoniana Wall, ex Bl.) wood under the scanning electron microscope are something like this: The growth rings can clearly be seen. The signs of changes from the early wood to the late wood are sometimes drastic and sometimes gradual. In the drastically changed growth rings, the axial resin canals usually spread only in the late wood, while in the gradually changed growth rings they spread almost in every wood. Their diameters are around 100-200 microns, with 6-9 eqithelial cells. There is only one radial resin canal in most of the rays, rarely two. The length of the diameter of the radial resin canal is one fourth of that of the diameter of the axial resin canal.