Abstract: Based on the monitoring date of acid deposition in Urumqi during the period from 2000 to 2009, in this paper the main characteristics of wet deposition were analyzed. The results show that wet deposition pollution was serious in Urumqi. Except the wet nitrogen deposition flux was 1.06 g·m^-2and similar to the average of whole China, wet sulfur and calcium deposition fluxes were 3.21 g·m^-2and 3.22 g·m^-2 respectively and higher than those in other provinces and cities in China. Wet sulfate deposition in Urumqi came mainly from the local SO2 sources, it became more and more serious in recent years, the contribution of nitrogen deposition to the total wet deposition was in an increase trend, and the decrease of wet calcium deposition may result in a more serious acidification of wet deposition.

Key words: pollution, deposition flux, acidification, atmospheric environment, Urumqi