Abstract: Thermal history reconstruction of the sedimentary basin is significant to the study of oil and gas exploration.The paleotemperature profiles reconstructed based on the vitrinite reflectance data from boreholes in the Sichuan Basin using a paleotemperature gradient method.The results show that the erosion in the top of the boreholes was about 3700 m in the western，southeastern and northeastern Sichuan Basin，while was about 3100 m in the central basin.The paleotemperature gradient ranged 13.2～24.5 ℃/km，and the paleoheat flow ranged 31.2～60.1mW/m2.The minimum value occurred at the L1 borehole which located in the Longmenshan foreland basin，northwestern Sichuan Basin，while the maximal value occurred at the W28 borehole which located in the Weiyuan uplift，southern Sichuan Basin.As a result of the structural and sedimentary action of the foreland basin evolution in Mesozoic，the heat flow was low in the Longmenshan and Dabashan foreland basins.