Abstract: Based on the thickness of the strata,the Late Permian-Eogene sediment flux of the Junggar Inland Basin is calculated in this paper.The results have revealed that the Late Permian is the main basin-forming stage in the light of the Late Permian sediment flux (18.297×10⁶ m³/a) higher by nearly one magnitude than that of Mesozoic and Eogene (1.735×10⁶ to 3.142×10⁶m³/a).The comparison of the sediment flux in different parts of the basin suggests that the sediment flux is highest in the southern part,higher in the northwestern part,and lowest in the northeastern part in the basin.It is deduced that the uplifting of the Palaeo-Tianshan mountain system is much stronger than that of other mountain systems,which may be related to the history of the frequent rises and falls of its basement,and to the pushing and extruding of the Tarim continental block.