Abstract:This paper reports the structures and formation of both lomasomes and plasmalemmasomes in the dikaryotic hyphae and conidium of the preceding fruitbody primordia of Tremellafuciformis. Both lomasomes and plasmalemmasomes are a membranous structures associated with plasmalemma. The presence of similar structures supports that the hypothesis of themultivesicular bodies or vesicles pass through the plasmalemma embedded in the cell wall and become lomasomes, which take part in cell walls synthesis. In the growing young cells during rapid division and single conidium, depressions of the plasmalemma prepuce vesicular plasmalemmasomes containing some vesicles, but then it also may produce membranous plasmalemmasomes. In themature cells, invaginations of the plasmalemma generally produce membranous plasmalemmasomes Projecting into the cytoplasm, which composed of a convoluted framework of membranes continuous with the plasmalemma and one to two electron-dense vesicles. When these two type of plasmalemmasomes casted off from the plasmalemma to migrate cytoplasm, a pet of membrane lamellae and vesicles were digested. Consequently, it can be reasoned that the plasmalemmasomes are the result of endocytosis of the plasmalemma in order for cellular growth and differentiation to transport material from the. substrate into the organism. The electron-dense cytoplasm of the cell adjacent to the septal pore which was blocked by folded sheet of endoplasmic reticulum. The invagination of the plasmalemma produce rare pocket plasmalemmasomes projecting into thecytoplasm, which composed of a unit membrane and three electron-dense vesicles. The formation and function of the pocked plasmalemmasomes are similar to the membranous plasmalemmasomes. It is considered that blocked septal pore and present of plasmalemmasomes are two important characters, which concerned with primordial cellular differentiation of Tremella fuciformis.Finally, the membrane lamellae of the membranous plasmalemmasomes can be disengaged to become endoplasmic reticulum which have been observed in the mature cell. Thus the endoplasmic reticulum also may be derived flom Plasmalemmasomes.