Due to its extremely sensitive to global climate change, the Qinghai Lake area is one of the most hottest research spots attracting global paleoenvironmental researchers. Qinghai South Mountain,situated in the northeast of Qinghai Province,is the boundary of Qinghai Lake Basin and Chaka Lake Basin. The loess can provide valuable archives for reconstructing Holocene paleo-environmental change. In the present work, the XL and XPS loess sections,located at the south and north of Qinghai South Mountain are examined by using sedimentology,geomorphology and geochronological methods. The chronostratigraphy is established by using nine optically stimulated luminescence (OSL) ages. The environment evolution records since the Holocene in the region of Qinghai Lake were rebuilt. We concluded that: (1) the aeolian sediment of Qinghai South Mountain changed from river deposits into aeolian accumulation at least 10.4 ka, indicating large climate transition; (2) During 10.4 ka ~ 5 ka, the loess dominated,occasional interbedded eolian sand thin layers,(3) During 3.4 ~ 1.0 ka, the pedogenesis was relatively strong, inferred a good combination of temperature-precipitation; (4) since 1.0 ka, the modern soil developed. These paleoenvironmental information of the Qinghai lake basin was generally in accordance to the Qinghai-Tibet plateau /environmental changes during the Holocene.