Abstract:The Jinbaotun basin is a Mesozoic intracontinental basin, in which coal-bearing strata are represented by the Upper Jurassic Xie'ersu Formation. It, 110 meters thick, is composed of greyish green, grey conglomerate and sandstone, greyish dark and dark fine sandstone, siltstone and mudstone and greyish white medium-coarse sandstone with coalbeds. Different environments of the basin are believed to occur in different phases of the basin evolution and in different places. In the lower part, the stage of deposition of the conglomerate member was mainly marked by the alluvial fan environment and the stage of depostion of the coal-bearing member was marked by the alluvial fan-fluvial-lacustrine environment association, which evolved into a meandering stream environment after coal formation. The stage of deposition of the sandstone-conglomerate member in the upper part mainly witnessed the sedimentation of braided stream deposits. Coal accumulation occurred in lake districts in the basin, in the early stage of the episode of en-masse stable and slow subsidence after the rapid subsidence of the basin. The coal bed directly covers lacustrine thick-bedded mudstone. The basin only experienced a cycle of rapid-slow subsidence, and the formation of the only coal bed was controlled by this "coal accumulation without oscillations".