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In this paper, the monitoring results and trends of six air pollutants including SO2, NO2, PM10, PM25, CO, O3 in Lhasa from 2014 to 2016 are analyzed and evaluated.In addition, the main factors affecting the quality of Lhasa’s atmospheric environment are also discussed. The results are as follows: (1) the main pollutants in the urban area of Lhasa were mainly PM10, followed by O3; (2) the content of SO2 and CO in the atmospheric environment decreased year by year during the observation period; however, the content of NO2 in the atmospheric environment over Lhasa showed a trend of increasing year by year during these three years; (3) the ratio of PM25/PM10 in the atmospheric environment of Lhasa was obviously low, indicating that the main influencing factors of atmospheric environmental quality in Lhasa are natural factors.