In order to study the elfeets of the prevention and contrl measures of COVlD-19 on the concentration and source of volatile organic compounds (VOCs) in different cities of Jiangsu Province, VOCs online monitoring instruments were used to monitor and analyze VOCs in Nanjing, Nantong and Xuzhou from January 1 to February 29, 2020. The results showed that after the prevention and control of COVID-19, the concentrations of total volatile organic compounds (TVOCs) in Nanjing, Nantong, and Xuzhou decreased by 35%, 35% and 54%, respectively. The most significantly affected species in VOCs were aromatic hydrocarbons in Nanjing and Nantong, and olefins in Xuzhou. The contribution rates of TVOCs to ozone formation potential (OFP) in the three cities decreased by 44%, 44% and COVID-19 VOCs 54%, respectively. The contribution rate of aromatic hydrocarbons decreased the most. The positive matrix factorization source analysis results showed that the prevention and control measures of COVID-19 had the most significant impact on the petrochemical and industrial solvent sources in Nanjing and Nantong. and had a great impact on chemical sources, motor vehicle emission sources and combustion sources in Xuzhou. In order to effectively reduce the VOCs concentration and the O3 generation , it was suggested to limit the VOCs emission from petrochemical and industrial solvent sources in Nanjing and Nantong. For Xuzhou, it was more effective to control VOCs emission from petrochemical and motor vehicle sources.