| Tibet Plateau is one of the most climate-sensitive area, the climate change on Tibet Plateau considered as key issue to understand the paleoclimate system.The formation and uplift of Tibet plateau had profoundly influence on global climate and environmental change. Our study area Hoh Xil which locates on the northwest of Tibet plateau is the biggest national nature reserve of China. The research area is lightly interferred by human activity and takes on nearly original natural state. Therefore, it is an ideal region to investigate regional climate evolution and its relationship with global climate.We took the106m deep drilling lake material cores in the Hohxil edge area of the region, and adopted tie points derived by matching the observed magnetostratigraphy to the geomagnetic polarity time scale (GPTS), developed an orbital tuned timescale for core BDQ06. The correct chronology was estimated from the experiment, which provides the possibility of comparison between regional and global climate. We analysed multi-proxies, such as the grian size, total orgnic carbon(TOC), Organic carbon isotope(δ13Corg), C/N, magnetic susceptibility, chroma and carbon and oxygen isotopes of carbonate(δ13Ccar,δ18Ocar), and reconstructed the history of evoluitons in palaeoclimate and palaeoenvironment since the Medio-Pleistocene. Furthermore, the climate change of our study area was compared with other geological record, the results indicated that there were very strong similarity with the scale of glacial-interglacial cycle, however there were also obvious regional differences. That is to say, our research area responded to global climate change with regional characteristics. Grain size parameters combined with deposition rate analysis showed there were three periods of markedly tectonic uplift of Qinghai-TibetanPlateau since Mid-Pleistocen,～0.60Ma,0.36Ma and0.16Ma, respectively.The results of power spectrum analysis revealed that climate evolution not only corresponded to earth orbital cycle, but also presented oscillations in millennium and ten thousand scales during past0.9Ma. Furthermore, the signal intensity of climate evolution cycle exhibited the obvious difference. The climate evolution presented strength41ka cycle, and weakly100ka cycle during0.84～0.78Ma, Strongest100ka cycle power spectrum occurred which was the dominant cycle of climate evolution, and it was not weakened until0.58Ma, when the climate evolution cycle was more complicated. All of these evidences support that100ka cycle exists over the past0.9Ma and it turned to be dominant cycle around0.78Ma.The uplift of Qinghai-Tibet plateau might have had an important influence on environmental change of study area. In particular, Kunhuang movement (～0.60Ma) drive plateau uplift to a critical height (about3000-3500m), and then the westerly was forced to divert and the aerological west storm tank was enhanced, which led to a fundamental shift of atmospheric circulation. After that, the Qinghai-Tibet plateau walked into cryosphere on a large range and the strong winter monsoon from the plateau blew into the Arabian Sea. Decreaed temperature of sea surface weakened the summer monsoon. As the result, the internal environment of the plateau was characterized by an obvious temperature change, even in the warm period the climate was still cool. The results from BDQ06borehole indicated that the climate fluctuation reduced significantly than that on the early stage, and all the indexes showed the lower temperature. In addition, the wavelet analysis of all the proxies from BDQ06borehole showed that100ka periodic signal was affected and became weaker. Climate change was not only forced by the orbital, but also forced by a quite proportion of the tectonic movement. Our results showed that climate change was very complex and had no explicit law in the study area. The uplift of the plateau at about0.36Ma caused the enhancement of the Asian winter and summer monsoon, but the uplift height and environmental signification still needed further research. Gonghe Movement (～0.16Ma) ultimately made the plateau uplift to the current height, which shaped the modern climate pattern.
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