The research includes afirst detailed study for ozone and nitrogen oxides NOx(NO+NO2) concentration in Mosul city using a monitoring station type Horiba. This research aims to find the monthly variation and the relationships of these gases with metrological factors. The site of general library in the City was selected for monitoring air quality. This site was nearby crowded streets and heavy traffic and intersections. The monitoring period started from 1/5/2013 to 30/4/2014. The research found that the mean concentrations of O3, NOx(NO,NO2)during the study period reached 0.0243, 0.0669 (0.0407, 0.0263) ppm respectively. The higher levels were recorded in the hot months for ozone, and in the cold months for nitrogen oxides. Spearman correlation test showed a significant reverse relationship of zone with nitrogen oxides, while the relationships among NO, NO2 and NOx were significantly positive. For the correlation with metrological factors, ozone correlated positively with temperature, sun light, wind speed and wind direction, while it correlated significantly negative with relative humidity and atmospheric pressure. On the other hand,a nitrogen oxide correlates negatively with the former group of metrological factors and positively with the later ones.