The outbreak of corona virus or COVID-19 pandemic has created a serious health concern worldwide. The world was forced to shut down. India witnessed nationwide lockdown from 25 March 2020 to 31 May 2020 in four different phases. Industries were shut and vehicle movement was restricted both in inter and intra state. In the present study, concentration of criteria pollutants, Surface ozone (O₃,),Sulphur dioxide (SO₂), Carbon monoxide (CO), Nitrogen Dioxide NO₂ and Total Suspended Particles (TSP)were monitored in pre lockdown period (PLD) 1 January-24 March 2020 and during lockdown (LD) 25 March-31 May 2020 were analyzed. Total Suspended Particles (TSP) were monitored by gravimetric method using Respirable Dust Sampler (RDS), NO₂ was measured using modified Jacob and Hochhesier method while sulphur dioxide, carbon monoxide and surface ozone were monitored using online gas analyzers manufactured by thermo fisher scientific at Mohal Kullu Valley of northwestern Himalaya which is a semi urban area.The results revealed reduction of 66.24%, 37.32%, 27.02 % and 16.67% in CO, TSP , NO₂ and SO₂ respectively during lockdown as compared to pre- lockdown while surface ozone (O₃) showed an increase in concentration during lockdown period as compared to pre lockdown. The overall air quality improved during the lockdown period when compared to the pre lockdown period in the valley indicating how the air quality is affected by anthropogenic activities in the area.