Deciphering the provenance of atmospheric dust is critical to understand the paleo-proxies archived in the eolian deposits on Chinese Loess Plateau. While most of evidences indicate major dust sources from the arid lands to the north and northwest of Chinese Loess Plateau,a recent research based on U-Pb geochronology of zircon renewed the hypothesis that the dust transported by westerly winds from north Tibetan Plateau and the Qaidam Basin might be the dominant eolian sources to Chinese Loess Plateau during glacial times. Here we test this hypothesis by analyzing ages of zircon in Xining loess. Xining (36.65°N, 101.74°E) is on the hypothetical pass way of dust transportation from north Tibetan Plateau to Chinese Loess Plateau. Compared with the loess on Chinese Loess Plateau,loess in Xining lacks zircon population with age around 360Ma and 〈 100Ma. In contrast, the materials eroded from Central Asian Orogenic Belt have large population of zircon aged ca. 360Ma and 〈100Ma. Although the major peaks of the zircon age distribution of Xining loess are very similar to that of the loess on CLP,the materials from north Tibetan Plateau could also be transported northwardly to the Alxa arid lands on the northwest of CLP. We thus conclude that loess on CLP is mainly sourced from the Alxa arid lands where materials are received from both north Tibetan Plateau( Qilian Mountains)in the south and the Central Asian Orogenic Belt( Gobi Ahay Mountains) in the north.