Abstract: The traditional methods with Kovats' retention indices or linear retention indices are used to identify the components for the PONA analysis of gasoline by gas-liquid chromatography. These methods exist some disadvantages to limit the scope of applications, such as multistage temperature programmed operation and analyses for poor-paraffin or rich-olefin gasoline samples. In the paper, a new concept simulation retention index is proposed and a method based on simulation index is developed for the PONA analysis of rich-olefin gasoline. The equation for the calculation of simulation index is the same as that for linear retention index. However, the meaning, calculation rules and scope of application of the simulation index are different from linear retention index. It is important to select rationally the reference peaks for new method with the simulation index. The ratio of chromatographic peaks to recognize accurately achieves over 99.5%.