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Abstract The fossil plants studied in this paper were collected from the Upper Carboniferous and Permian in Liujiang Basin, Hebei Province. This flora was composed of 86 species in 44 genera belonging to Filicopsida (41.8%), Cycadopsida (4.6%), Cordaitopsida (2.3%), Ginkgopsida (2.3%) and Coniferae 2.3%.x Many fossil plants had the characteristics of Cathaysia flora. The flora could be divided into six assemblages in ascending order:Linoptleris neuropleroides-Lepidodiendron galeatum, Neuropteris plicata-Lepidodendron posthumii, Lobatannularia sinensis-Annularia stellata, Pecopteris anderssonii-Pterophyllum daihoense, Cladophlebis permica-Psygmophyllum multipartitumand Uilmannia bronnii-Walchia bipinnata assemblages. According to the sedimentary characteristics and plant assemblages, the evolution of the flora could be divided into six stages. In the first stage(Benxi Formation) deep subtidal，lagoon,delta and river occurred allernativelyIn the second stage (Taiyuan Formation), subtidal，tidal flat and delta occurred alternativelyIn the third stage (Shanxi Formation), swamp, distributary channel, natural levee,and crevasse splay occurred alternatively. In the fourth stage (Lower Shihezi Formation), swamp, distributary channel, and sand bar occurred alternatively. In the fifth satge(Upper Shihezi Formation), large lake lake, natural levee,and river mouth bar changed to point bars and central bars. In the sixth stage(Shiqianfeng Formation), large lake delta, natural levee, river mouth bar and point bar ocurred alternatively.Key wordsLiujiang Basin, Carboniferous,Permian, Cathaysia flora, evolution of paleaogeographyAbout the authorYang Tongsheng，born in 1958，graduated from China University of Geosciences(Beijing) and obtained Ph. D. degree in 1999.Now he is an associate professor,and is engaged in paleobotany，sedimentary environments and paleoecology.
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