Owing to increasingly strict emission regulation, gasoline properties not only satisfy the needs of high performance for the engine, but also attain the requirement of vehicles exhaust control. The gasoline from gas stations around China is sampled and its properties are analyzed. The distribution of gasoline quality in different zones is listed. At the same time, the difference of properties between domestic and oversea gasoline is compared. After establishing the emission model of the engine, the reference value of vehicle emissions in different zones is obtained. At last, some measurements are proposed to reduce the emissions: improving gasoline quality and controlling the related parameters for engine according to the distribution of gasoline properties.