Abstract: Luohe formation in Wunuer area，Great Hinggan Mountains is locate in the accretion zone of the Paleozoic continental margin of the southeast Siberian plate，it's a "window" to recognize Central Asian Orogenic Belt's trencharc system.In order to understand the sedimentary characteristics and source properties of the Luohe formation and enrich the study of sedimentary strata in Central Asian Orogenic Belt's trencharc system,Using sedimentary geology and petrogeochemical methods,the sedimentary geological characteristics and sediment source are analyzed and studied，Based on these works， three following understanding can be found:①Parallel bedding and horizontal bedding are developed in the Luohe Formation，Three main basic sequence types can be seen.②The results of sediment grain size analysis show that the Luohe Formation is shallow sea facies deposit.③The characteristics of major elements，trace elements and rare elements indicate that the sediment source of the Luohe Formation was formed in an island arc environment．

Key words: great khingan mountains, luohe formation, sedimentary geological characteristics, sediment source