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Climatic oscillations have been developed through the (Early) Jurassic from marine sedimentary archives but remain unclear from terrestrial records. This work presents investigation of climate-sensitive sediments and carbon and oxygen isotope analyses of lacustrine and pedogenic carbonates for the Early Jurassic Ziliujing Formation taken from the Basin in southwestern China. Sedimentary and stable isotope proxies manifest that an overall secular (semi)arid climate dominated the Sichuan Basin during the Early Jurassic, except for the Hettangian. This climate pattern is similar to the arid climate in the Colorado Plateau region in western North America but is distinct from the relatively warm and humid climate in northern China and at high latitudes in the Southern Hemisphere. The estimated atmospheric CO 2 concentration (p CO 2) from carbon isotopes of pedogenic carbonates shows a range of 980–2610 ppmv (∼3.5 –10 times the pre-industrial value) with a mean of 1660 ppmv. Three phases of p CO 2 (the Sinemurian 1500–2000 ppmv, the Pliensbachian 1000–1500 ppmv, and the early Toarcian 1094–2610 ppmv) and two events of p CO 2 rapidly falling by ∼1000 –1300 ppmv are observed, illustrating the p CO 2 perturbation in the Early Jurassic. The perturbation of p CO 2 is compatible with seawater temperature and carbon cycle from the coeval marine sediments, suggesting a positive feedback of climate to p CO 2 through the Early Jurassic. [ABSTRACT FROM AUTHOR]