There is great difference in the sedimentary environment and depositional system of different formations of the Silurian in Tarim Basin.By combining the detailed observation and description of the cores with logging data,regional geological data and various laboratory analysis identification data,based on the analyses of the lithology and sedimentary structure,the sedimentary characteristics and sedimentary facies of Kepingtage Formation are thoroughly studied.It is held that deltaic,estuary and tidal flat depositional systems are mainly developed in Kepingtage Formation.Based on the study of the depositional systems,the corresponding sedimentary mode diagrams are established.