The atmospheric air is being polluted by urbanization, industrialization, by anthrogenic activities and the pollutant gases Sulphur dioxide, Nitrous oxide, Ozone gas, Carbon Monoxide and invisible particulate matters pH10& pH25 cause respiratory disorders to human beings on the Earth. A critical study air on quality Index (AQI) of different cities of India is carried out in the present paper, basing on the data provided by State and Central Pollution Boards. Average monthly values of air quality for the year 2018 of some cities are taken and the results were studied. The results reveal that out of 37 major cities in Andhra Pradesh, 10 cities recorded unhealthy moderate AQI pollution levels (99-112) and the remaining cities are up to the satisfactory mark (62-89). And out of 8 metro polities of India, Ahmedabad & Mumbai showed 110 & 546 AQI values respectively and Mumbai showed highest 440 PM10 and 213 PM25ug/m3 values which are 4-6 fold high to the permissible values. So, it is concluded that sincere awareness is required to the people about the quality of air.