Based on the national highway traffic information, NO_x and VOCs emissions have been calculated in the Pearl River Delta during summer by GIS road network linear reference system, and the maximum incremental reactivity (MIR) and empirical formula were used to estimate the O₃ generation of VOCs and NO_x and spatial distribution characteristics of O₃, respectively. The proportion of emissions of VOCs in summer was generally consistent with the proportion of vehicles of various types, while the proportion of NO_x emissions of gasoline vehicles was significantly different from the number of vehicles. And the distribution of VOCs emissions was similar to that of NO_x. Guangzhou was the city with the highest emissions of NO_x and VOCs, and the emissions of Zhuhai, Zhongshan and Jiangmen were relatively small. The total amount of O₃ produced by NO_x was inversely proportional to the production capacity. The olefin and aromatic hydrocarbons shared the highest O₃ production rate in all vehicles, while the alkane with the largest emissions produced the lowest O₃ content. In Guangzhou and Shenzhen, where the road network density was high, the amount of NO_x and VOCs emitted by automobiles was relatively high, and the O₃ concentration produced by them was also high. For cities with low road network density (such as Zhuhai City), O₃ pollution was mainly spread out on the main line of transportation, and O₃ were small.