四川盆地是我国重要的含油气盆地之一，素以“冷盆”著称，地温梯度（２．０～２．５）℃／１００ｍ。但近年来通过镜质体反射率法、矿物包裹体测温法、粘土矿物相转变法以及裂变径迹法等多种手段进行古地温研究之后发现，四川盆地早白垩世末至始新世期间古地温梯度曾高达（３．２～４．８）℃／１００ｍ，上三叠统底部最高古地温曾高达１６０～２８０℃。高古地温对于四川盆地天然气的生成和超低孔渗储层的致密化作用均有重要影响。 The Sichuan Basin is one of the most important petroliferous basins in China. It is known as a “cold basin,” and its geothermal gradient (2.0 ~ 2.5) ℃ / 100m. In recent years, however, studies on paleo-geothermal temperature by means of vitrinite reflectometry, temperature measurement by mineral inclusions, clay-mineral phase transformation and fission-track methods have revealed that during the period from the Early Cretaceous to the Eocene in the Sichuan Basin, The paleogeothermal gradient reached as high as (3.2 ~ 4.8) ℃ / 100m, and the highest Paleogene temperature at the bottom of the Upper Triassic reached as high as 160 ~ 280 ℃. The high paleo-geothermal temperature has an important influence on the formation of natural gas and the densification of ultra-low porosity and permeability reservoirs in the Sichuan Basin.