Air quality has been a matter of public concern in Delhi. The concentration of Particulate Matters (PM_2.5 and PM₁₀) often surpasses the Indian National Ambient Air Quality Standards (NAAQS). This study is focused upon the evaluation of Environment Pollution (Prevention and Control) Authority (EPCAs) Graded Response Action Plan (GRAP) action during 2018 in terms of PM_2.5 and NO₂. In order to control air pollution sources in National Capital Region (NCR), the (EPCA) Environmental Pollution (Prevention and Control) Authority directed GRAP to advise the local industries and other sources of pollution to close their operations on particular dates whenever Air Quality Index (AQI) showed severe level. In this study, we have analyzed 24 hourly averaged Air Quality Index (AQI) data for the period September 2017 - January 2018 and September 2018 - January 2019 at two sites i.e. Delhi Technical University (DTU) and Income Tax Office (ITO) respectively. The GRAP results showed a significant decrease in AQI values of both after every order passed by GRAP task force. In general, the PM_2.5 AQI values were always higher during year 2017-18 as compared to 2018-19 at both sites.