Since volatile organic compounds (VOCs) are important precursors of ozone (O3), identification and quantification of their emission sources are prerequisite for the formulation and implementation of O3 pollution control policies.In this study, source apportionment via Positive Matrix Factorization (PMF) was carried out on the VOC data continuously sampled at a site in Nanjing Northern Suburb, and five major sources of VOCs were identified.Contributions of VOCs to photochemical O3 formation were evaluated by the application a detailed chemical mechanism model (NCAR MM).The chemical mechanism model calculation showed that different VOC species had very different contributions to the high ozone concentrations, and the analysis suggested that the alkene was a main contributor for the O3 chemical production in Nanjing Northern Suburb.This analysis implied that future increase in alkenes emissions could lead to significant increase in O3 concentrations in Nanjing Northern Suburb.Based on the outcomes of the PMF source apportionment, a sensitivity analysis on the basis of relative O3 reduction efficiency (RORE), under different source removal regimes such as using the reduction of VOCs from 10% to 90% as input, was conducted and results indicated that the O3 reduction was the most effective when the identified VOC sources were cut by specific percentages.This study provides valuable insights into the formulation and implementation of VOCs and O3 control strategies in Nanjing Northern Suburb, using a combined field measurements and modeling approach.