With the data of daily outpatient visits of allergic rhinitis, air pollution and meteorological data in the three cities of Lanzhou (2014-2016), Tianshui (2016-2018) and Zhangye (2016-2018), this study analyzes the relationship between relative humidity (RH), absolute humidity (AH) and the daily outpatient visits of allergic rhinitis. In the three cities, the peak period of daily outpatient visits for allergic rhinitis is from August to September. The decrease in RH could lead to significant increase in outpatient visits for allergic rhinitis in the three cities. With the each 1% decrease of RH, the outpatients visit for allergic rhinitis in Lanzhou, Tianshui and Zhangye could increase by 1.36%, 2.30% and 1.50%, respectively, while the outpatients visit for allergic rhinities in the three cities have the increase of 14.92%, 16.00% and 13.98% accordingly for each 1 g·m-3 decrease in AH. Our study suggests that the onset of allergic rhinitis is negatively associated with atmospheric environmental humidity, and the dry and lowhumidity environment is an important risk factor for allergic rhinitis in arid area. Compared with RH, AH could better reflect the effect of environmental humidity on allergic rhinitis