Abstract: To study the influence of meteorological conditions in south Hebei on air pollution and the effects of emergency emission reduction (e.g. during the 70^th anniversary of the victory of the anti-Japanese war), the authors took Handan which located in south Heibei as an example, analyzed the monitoring data between August 1^st and September 3^rd, 2015 from Handan environmental monitoring station and the meteorological data from Handan meteorological station. The results showed that: during the period of emergency emission reduction (from August 23^rd to September 3^rd), the atmospheric pollutant concentrations in Handan decreased significantly, and the average concentration of PM_2.5 of the whole city decreased by 46.3% compared to the days (from 1^st to 22^nd August) before the emission reduction was implemented, the air quality in the whole city from 1^st to 3^rd September reached the first level. The comprehensive analysis of the inversion intensity, mixing height, ventilation coefficient, wind speed, days of light wind speed, precipitation and other meteorological conditions and the backward trajectory showed that: most of the time during the emission reduction was affected by the stable synoptic situation, which was not conducive to the vertical diffusion of air pollutants; the analysis of air mass backward trajectory showed that: the local air mass was dominating; the emergency emission reduction significantly decrease the concentration of pollutants under the same meteorological condition, so the powerful emission reduction measures were the fundamental means to improve air quality.