Abstract: The hyphae of endomycorrhiza of Galeola faberi can't grow in vitro. The fibrous infection hyphae invade epidermis of lateral roots of Galeola faberi, and is formed an infect cavity in periphery of the cortical tissue. Infection proceeds toward the middle of cortical tissue and infection passage parallel to the vertical axis of lateral roots. The growing point of infection hyphaeare very turgid. The hyphae in the infection passage penetrated into cortical cells through pits and ramify in the cells with haustoria formed at the ramose tips. Nuclei in infected cells re main uncharged, but the cytoplasm became sparse. Them symbiotic state so formed remains relatively need. The cell walls of the inner 6—8 cortical cell layers thicken and lignify bala, so that, infection by hyphae is largely prevented. Only a few hyphae enters into the cells and form typical haustoria. A lot of secondary metabolites are released when the haustorium senescence and collapse. These metabolites are transported to the phloem through pits and provide nutriuts for growth and development of Galeola faberi.Small amount of RNA and protein were found in the cytoplasm of the mycorrhiza, although they were rich in the nucleus. Traces of DNA and arginine were detected in the arbuscules and haustoria, but reactions of RNA and protein were inconspicuous. The arbuscules contained lipids, but not detected in the senescent haustoria. All arbuscules and haustoria were rich in amylopectin (red starch). Callose and polyphenol compound were found at the hyphase passage way on the plant cell wall. Net work of chitine was found in the wall haustorium.Under the ttansmission electron microscopy, the highest electron density of cytoplasm was observed at the early stage of the arbuscular trunk. It contained a little vesicle and a layer cf interfacial material from cytoplasmic hyperplasia of host, and this interracial material of membranous structure surround the hypha, and the structural features of this intergacial material were similar to Gastrodia elata. Following the development of the hyphae, the arbuscular trunk and haustorium gradually decrepitude, and the electron density material were lost. As the outer single membrane round the haustirium disrupted, the pentagonal membranous structure were released, and at last, the arbuscular trunk become an empty cavity.The renewable arbuscular trunk were formed at the basic region of the decrepit one. It contained two nuclei and the structure are clearly. Before the infection of host cells, the organelle are amyloplast mitochondrium, dictyosome and a little endoplast reticulum and ribosome. After the infection, the members of organelle occured change. It consist of microfilaments, small vacuole and multivesicular bodies which play a part in transfer and hydrolysis of material within the cell. In this paper, the difference and similarities on the ultrastructure among the Galeola faberi with V-AM and Gastrodia elata were disscussed.