Abstract:Objectives:The Sikouzi Section, Guyuan, Ningxia, locates in the convergence zone of East Asian monsoon region and Central Asian drought region. The climate evolution history of the Sikouzi Section during the Cenozoic time is crucial for understanding the continental climate respondence under the background of global cooling and revealing whether global cooling or the uplift of Tibetan plateau is the first-order driver for aridification of Central Asia. Methods:Sediment color is a sensitive and useful index to record paleoclimate change. We adopted this index for the Sikouzi Section. Results: By measuring the fluvial-lacustrine sediment color proxies (a*, L*, b*) of the Sikouzi Section, we establish high-resolution color sequence from late Oligocene to Quaternary (29~0.5 Ma). Integrating published susceptibility (SUS), pollen and total inorganic carbon (TIC) data, we reconstruct regional climatic evolution history since 29Ma. The multiple proxies unravel four climate events: 25~24 Ma, 18 Ma, 5 Ma cooling events and 3Ma warming events. Conclusion: Comparing climate proxies of other Cenozoic basin in northeastern Tibetan Plateau, these climate events are regional events, but climatic changes has regional discordance during 12~5 Ma. By sorting out the records of the deep sea oxygen isotopes, the dust fluxes in the northern Pacific Ocean, the tectonics of Tibetan Plateau and the climate evolution of study area, we speculate that regional climate evolution is controlled by the tectonics of Tibetan Plateau and global climate change. However, tectonics and climate factors play different roles in certain periods.