The mixed sediments are widely developed in marine and lacustrine sedimentary environments.This paper overviews the research status and its relationship with oil and gas enrichment based on the systematic analysis of the genesis mechanism,type of assemblage,sedimentary model and sequence stratigraphy,controlling factors,reservoir development and hydrocarbon accumulation in mixed sediments.Based on a large amount of data,the paper describes the genetic mechanism,formation conditions,controlling factors,sedimentary model and the relationship between oil and gas accumulation in the Permian Lucaogou Formation in the Jimsar Sag,Junggar Basin.The mixed deposition is controlled by many factors such as tectonic setting,sedimentary environment,provenance,sea/lake level change,tectonic movements,hydrodynamic and climate change,but carbonate is the basic condition for its formation.The existing research results about the mixed sediments are obviously regional with no comparative analysis on the lithology,mixed types and control factors of mixed deposition in different sedimentary environments.Future research should focus on the mixed sedimentary and sedimentary systems,the relationship between sequence stratigraphy and its reflections on paleogeography,paleo-sediment environment and antiquities.The relationship between mixed sedimentation and hydrocarbon enrichment is very close,and because of their different lithologies,they contain not only the original organic matter,but also a variety of types of pores.Therefore,there is an inherent genetic relationship between the organic matter enrichment characteristics and the development of different pore types,which is an important part of oil and gas geology research in the future and is of great significance to the enrichment of unconventional oil and gas.