This paper analyses the sequence stratigraphy and palaeogeography of the Lower and Middle Jurassic coal measures in the TurpanHami Basin， northwestern China. The controls of the palaeogeography and sequence stratigraphy on the coal accumulation in this Basin have been discussed. The results show that the coal measures were formed in a fluvial-delta-lacustrine sedimentary system， and a total of 4 thirdorder sequences were developed， corresponding to the Badaowan Formation， Sangonghe Formation， the Members 1， 2 and 3， 4 of the Xishanyao Formation， respectively. The TurpanHami Basin had experienced the swamping（Sequence Ⅰ）—lake flooding（Sequence Ⅱ）—swamping（Sequence Ⅲ）—lake flooding（Sequence Ⅳ）processes. The thick coal seams were developed during the deposition of the late transgressive systems tract and the early highstand systems tract corresponding to the maximum flood surface， when the rate in creation of accommodation kept balance with the peat accumulation rate. There is a negative correlation between the thickness of coal and carbonaceous mudstone and the content of sandstones and conglome￣rates，ie. the thicker coals are associated with the lower contents of sandstones and conglomerates. This implies that the coalforming environments are interdelta bays， lower delta plains and back swamps in the fluvial system. The thickest coal seams occur in areas with a strata thickness ranging between 300～500m for Sequence I and between 400～550m for Sequence Ⅲ. This suggests that the most ideal sites for coal accumulation are those with moderate rates of subsidence and relatively little input of coarsegrained sediments， which favors the development of interdelta bays， lower delta plains and back swamps in fluvial systems. The coalaccumulating centers during the deposition of sequence I and sequence Ⅲ in the TurpanHami Basin， such as Ewirgol， Kerjian， Taoshuyuan， Qiquanhu， Kekeya， Shanshan， Aidinghu， Shaerhu， Dananhu and Sandaoling， were developed in these environments.