Human development activities should be incorporated as integral components of Earth's ecosystems.The land use/land cover change with rapid urbanization,especially the growth and spread of impervious surface,was changing the structures,degrading the functions of the urban ecological systems and posing threats to air quality.The ISC had been recognized as a geographical indicator to reflect the intensity of human development activities.The ISC in the BTH,which were interpreted from Landsat imagery,rose from 0.7% to 1.5% during 2000 to 2014.The mean of the PM_2.5 concentration had soared from 45.7 to 77.3μg/m³.We stratified the BTH by differences in the PM_2.5 concentration between 2000 and 2014 into slight (0~9.9μg/m³),moderate (10~29.9μg/m³),heavy (30~49.9μg/m³),hazardous (50~77μg/m³),the area for slight,moderate,heavy,hazardous was 42374,90700.5,60635.1,and 20279.0km²,respectively.The result revealed that the hazardous zone (Beijing-Langfang-Tianjin-Tangshan along the highway G1 and BeijingBaoding-Shijiazhuang-Xingtai-Handan along the highway G4) were accompanied by the ISC growth rate of 208.3%.Meanwhile,the spatial distribution of PM_2.5 aggravation was consistent with the impervious surface expansion in the BTH region,such as the growth rate of the ISC in the southeast (160%) was greater than that in the northwest (50%),and the increase of the PM_2.5 concentration in the southeast (45.5μg/m³) was also greater than that in the northwest (17.0μg/m³).Moreover,at the county level,we had found that larger county,in term of the ISC,have higher PM_2.5 concentration.176counties within BTH region were stratified by ISC into unstressed (0~4.9%),lightly stressed (5%~9.9%),stressed (10%~14.9%),impacted (15%~24.9%),degraded (>25%),and the corresponding mean of the PM_2.5 are (42.7±10.5),(79.9±11.9),(95.6±15.4),(99.1±10.8),(115.3±9.2)μg/m³,respectively.The unstressed counties had 0~5% imperviousness and typically had good air quality,and the counties have 5%~25% imperviousness and showed clear signs of degradation.The degraded counties have >25% imperviousness and averaged (115.3±9.2)μg/m³ of the PM_2.5 concentration,reaching three times that of the unstressed counties.The proportion and spatial distribution of impervious surface should be considered in the National New-type Urbanization development of China,making the cities surrounded by enough greenbelt and water areas and controlling the county with ISC <25% on the basis of the existing impervious surface spatial distribution to form a remedy for the PM_2.5 pollution.