Abstract: This paper has reported systematically on the wood ultrastructure of Pinus massoniana Lamb.It includes:bordered pits,microfibrillar orientation in the different layers of cell wall,warty layer and crystals.It is the first report on the occurrence of crystals in the pit chambers and on the inner layer of secondary wall or warty layer of tracheids and the lumen of ray parenchyma cells of this pine.These crystals are formed as a result of fungal metabolism of wood all along the hypha.Since the hyphal strands penetrate into the parts as above, crystals can also be found there.This means that anatomists can not classify the crystals as a normal structure to be useful in identifying this pine.This paper has pointed out the difference of pit structure between the sapwood and heartwood,earlywood and latewood,a evidence of the primary structure of torus,the permeability of wood is easier in sapwood and latewood than in heartwood and earlywood,and their causes are indicated too.On the surface of the layer S₂ appearing some random orientation of microfibrils,the author considers that may be the connected layer from S₂ to S₃ or the outer surface characteristics partially on the layer S₃.The sections treated with 0.25% sodium hypochlorite for partially delignification,the warty layer on the inside of tracheid lumen looks like decreasing in quantity and size clearly,and sometime it is not easy to be seen under TEM.