Abstract: In order to study the chemical components and sources of volatile organic compounds （VOC_S） in Mengzi City,Honghe Prefecture,offline monitoring equipment was used to continuously observe the chemical components of VOC_S in Mengzi City from April 14 to April 19,2021.The results showed that through the analysis of VOC_S mass fraction in Mengzi City,high-carbon alkanes were the most important components of volatile organic compounds;through the analysis of ozone generation potential （OFP） in Mengzi City,non-methane hydrocarbons had the highest activity,The contribution to OFP was 77.71%,of which n-butene was the largest species of OFP;according to the sensitivity analysis of ozone generation,most areas of Honghe Prefecture,including Mengzi City,belong to the VOC_S control area;The overall trend was"high at night and low in the daytime";the source analysis results showed that the main source of VOC_S in Mengzi City was industrial emission source.