To study the Arbuscular mycorrhizal (AM) formation progress and infection characteristics between tissue culture plantlets of Pinellia ternata and Glomus mosseae. The tissue culture plantlets of P. ternata were inoculated with G. mosseae, the formation of AM were sampled and observed with microscopy by staining. The hyphae of G. mosseae began to penetrate the root epidermis after 10 days of inoculation. Lots of intracellular hyphae formed in cortex cells at the 15th day. Arbuscules started to form and there were some hyphae on the root at the 20th day. At the 25th day, many arbuscules formed and most as Arum type. Some arbuscles started to disintegrate at the 30th day, and a few of vesicles occurred. Lots of spores formed after 35 days. At the 40th day, some vesicles began to decline. The hand section showed that the intercellular hyphae gradually formed in intercellular space, and the hyphae branched in cortex cells and occupied most cell lumen finally. It is expounded that P. ternata and G. mosseae could recognize each other quickly and form a symbiont system.