Abstract: The fluid inclosion petrography and thermometry of quartz vein and quartz-calcite vein from two boreholes and a Carboniferous surface section in Jungar basin were studied. By combined use of vitrinite reflectance data, the thermal history, hydrocarbon formation and evolution of source rocks in the basin were discussed in detail. Furthermore, the thermometry of fluid iuclosion with quartz-calcite vein and its geological significance were reviewed.