Major soluble ions were measured in 26 aerosol samples collected at Glacier NO. 1 at the headwater of Urumqi River in Tianshan Mountains in April, August and October 2007. The concentration, seasonal change and source of aerosol were analyzed. The results showed that the mean concentration of total soluble major ions of aerosol was 2.76 microg.m-3, Ca2+, NO-(3) and SO2-(4) were the major soluble inorganic ion components. In spring, summer and autumn, the seasonal change of the mean concentration of total soluble inorganic ions was consistent with Ca2+ , SO2-(4) , NH+(4), Na+ , Mg2+ and Cl- , the highest concentration was in summer, followed by autumn and spring. While the maximum concentration of K and NO-(3) was observed in autumn, the minimum was in spring. Soluble inorganic ion source characteristics were that: Ca2+ , Na+, Mg2+ , K+ and Cl- were mostly the land source; NO-(3) and NH: were mainly from the anthropogenic source. SO2-(4) was mainly originated from both crustal surface and anthropogenic sources.