In this study, ambient ozone (O-3) pollution characteristics and sensitivity analysis were carried out in Yulin, a city in the central area of the Loess Plateau during 2017 to 2019 summer. O-3 concentrations increased for 2017 to 2019. Correlation and statistics analysis indicated high temperature (T > 25 degrees C, low relative humidity (RH < 60%), and low wind speed (WS < 3 m/s) were favorable for O-3 formation and accumulation, and the O-3 pollution days (MDA8 O-3 > 160 mg/m(3)) were predominantly observed when the wind was traveling from the easterly and southerly. O-3 concentration in urban area of Yulin was higher than that in background. The pollution air masses from Fenwei Plain increase the level and duration of O-3 pollution. In order to clarify the formation mechanism and source of O-3, online measurements of volatile organic compounds (VOCs) were conducted from 7 July to 10 August in 2019. The average of VOCs concentration was 26 +/- 12 ppbv, and large amounts of alkenes followed by aromatics, characteristic pollutants of the coal chemical industry, were detected in the ambient air. To further measure the sensitivity, the observation-based model (OBM) simulation was conducted. Empirical Kinetic Modeling Approach (EKMA) plot and relative incremental reactivity (RIR) value indicated Yulin located on VOCs-limited regime. That implied a slight decrease of NOx may increase O-3 concentration. When the emission reduction ratio of anthropogenic VOCs/NOx higher than 1:1, the O-3 will decrease. O-3 control strategies analysis shows that the O-3 targets of 5% and 10% O-3 concentration reductions are achievable through precursor control, but more effort is needed to reach the 30% and 40% reduction control targets.