The lithofacies and sedimentary facies of modern Chaobai River in Baimiao（Tongzhou district in Beijing） are detailedly studied by digging deep trenches, pits and field profile. It is shown that Baimiao is a meandering river sedimentary body. Eight lithofacies are identified, and they are massive bedding fine conglomerate（clay gravel-based）, large-scale low-angle trough cross bedding fine sandstone，low-angle trough cross bedding fine-grained sand-stone, synsedi-mentary distortion bedding fine sandstone, parallel bedding fine sandstone, tabular and wavy cross bedding fine sandstone, thin massive bedding siltymudstone and fine sandstone and massive beddingmuddy siltstone. Two subfacies developed and they are river channel and flood plain sub-phase. Five kinds of microfacies named riverbed, point bar,levee, crevasse splay and floodplain developed in Chaobai River in Baimiao. Sedimentary body of Chaobai River developed three sedimentary cycles in vertical and they are controlled by sediment supply, climate and quality of river banks. The analysis of lithofacies and sedimentary facies is significant for finding lithologic reservoir and the development and utilization of Chaobai River.