Paleosols, recorded the features of superg ene environment during soil formation, are ideal archives for paleoenvironment and paleoclimate reconstruction. Numerous pedogenetic signatures in deep-time (i.e., pre-Quaternary) paleosols did not occur in adjacent sedimentary strata, in spite of the morphological difference from modern soils due to the effects of long-term burial and diagenesis. Morphological characteristics on soil horizons, root traces, new growth and micromorphological features were helpful for paleosol identification. Elemental geochemistry and carbon and oxygen isotopic compositions from pedogenic carbonate were the main ways to estimate the development degree of paleosol as well as the reconstruction of paleoenvironment and paleoclimate. Critical events in the environmental and climatic change during the geological past, e.g. atmospheric composition and biological evolution in Precamhrian and Devonian, abrupt climate change in the latest Permian, atmospheric CO_2 fluctuation in Cretaceous, hot climate in the early Eocene, and plateau uplift in the late Cenozoic had been revealed by paleosols, which demonstrates that the paleosol investigation played an important role in understanding the deep-time Earth surface system. The further research should be studied on the effects of burial and diagenesis on paleosols, environmental proxy selection, model of paleoenvironment reconstruction, and temporal-resolution.