Clastic and carbonate rocks are produced fromexogenous,muddy waterandendogenous, clean waterenvironment,respectively. The frequent alternations of clastic and carbonate facies reflect the repeated,major changes in multiple environmental factors,such as the nature of palaeowater, sediment supply and palaeoclimate. During the Late Carboniferous,the northern Qaidam Basin is tectonically inactive,and thus providing conditions for development of extremely thick mixed clastic-carbonate deposits, which consist of multistage cycles,recordingicehouseinformation such as the glacier activities and their influence to the palaeo-sea level fluctuations as well as the frequent palaeoclimate and palaeoenvironment changes. The continuous outcrop and core section from the northern Qaidam Basin are taken as the research object. In association with regional geological data and previous research results,we identify the clastic incised-valley fills and carbonate platform deposits,which are frequently alternated and constituted the mixed strata,in the target interval of the study area. The orderly superposition of the clastic-carbonate sequence succession in the vertical direction constitutes a complex sea-level change cycle sequence. The vertical change from the deformed carbonate platform to the lower river-dominated incised valley and then to the upper estuary bay-fill sequence towards flooding mudstone,into the carbonate platform from seaward to landword, suggesting a complex sea-level change cycles,which are expressed as the early regression initially the gradual transgression in the middle periodthe returned regression in the later stage. The obviously cold climate weather during the glacier period and the intensive glacioeustatic change,with high-amplitude sealevel rise and fall,have driven the migration of the shorelines and facies belts,and have contributed to the clastic-carbonate successions by affecting the supply rate of the clastic rocks and the productivity of the carbonate rocks,leading to the frequent conversion of clastic and carbonate strata.