A lot of well-preserved plants from the Linxi Formation are collected in the Soron area，Inner Mongo- lia，consisting of 34 species of 16 genera． They are Late Permian in age． The flora is characterized by a lot of Angaran plants，such as Paracalamites，Comia，Ｒhachiphyllum，Iniopteris，Ｒufloria，etc． Some Cathaysian ele- ments，such as Lobatannularia lingulata，L． multifolia，Fascipteris Cathaysiantus，F． densata，Taeniopteris szei，Cladophlebis liulinensis and C． permica，are also mixed within the present flora． This indicates that the So- ron of Inner Mongolia was located in the sector between the Angaran and Cathysian floristic provinces in Loping- ian． It is beneficial for depicting the location and the evolution of the Solenker--Xar Moron suture zone in the phytogeographic view． The transmigration of tropical and subtropical Cathaysian plants to the north indicates that the Paleoasian Ocean was closed during the late Permian along the suture zone．