By analyzing O3 concentration,NOx concentration and intensity of illumination in Shihezi City in summer of 2015-2018,the relationship between O3 concentration and NOx concentration in summer was obtained.The results showed that O3 concentration rise was 14 h later than NO2 concentration rise when O3 concentration exceeded the standard in Shihezi in summer.Meanwhile,NO2 concentration had certain effect on O3 formation.