In this study we pursued regional air quality modeling over Hebei and surrounding areas and analyzed the regional contributions to the PM_2,5,concentrations and light extinction coefficient. The re- salts show that the largest contributor of PM_2,5 is Hebei province with the number of 67.9%,followed by Shanxi (7.38%),Henan ( 6. 95 %),Shandong (5.48%)and Beijing一Tianjin(1.09%).)n the modeling period, the contributions to the light extinction coefficient are 64.7% for Hebei, 11. 2% for Shanxi,3.5% for Shandong, 4.8% for Henan and 1. 1% for Beijing-Tianjin.