The Kucong, a branch of Lahu and an indigenous ethnic group living in Jinping County, Yunnan Province, China, have a very short history of settled village life (about 40 years). According to the data of ethnobotanical investigation, 118 species of medicinal plants belonging to 57 families and 98 genera used by Lahu healers have been inventoried. The characteristics of medicinal plants coming from a great number of families and genera relate to the traditional life-style of the Lahu. The more common the diseases are, the more abundant the related medicinal knowledge is. The most frequently used parts of medicinal plants are the leaf (35.22%) and root (32.08%). The disappearance of environments related to the traditional life-style of the Lahu threatens the existence of their traditional medicinal knowledge, similar to threats facing many other traditional medicines. Collection and inventory should be essential research fields in studies of traditional medicine.