Abstract: The portable emission measurement system (PEMS) devices for real driving emissions (RDE) test can eliminate the compliance of emission standards in a special laboratory which can more accurately reflect the emission level of the vehicle in real driving, providing an efficient method for determining vehicle emission defects. In this study, a gasoline vehicle was tested many times using PEMS in accordance with the RDE test procedure to analyze the relationship between the vehicle driving features and CO<sub<2</sub< window normality. Results show that, the CO<sub<2</sub< result is correlated with the speed and acceleration distribution of the vehicle in real driving. In the RDE test, it is found that when the acceleration distribution is consistent separately with WLTC low, high and superhigh acceleration distribution, the RDE can easily to pass the normality verification. And then, a one-to-one correspondence was produced about the driving features between RDE and WLTP Test, including urban to low speed interval, rural to high speed interval and motorway to extra-high speed interval. Finally, the coefficients of reference points <i<P</i<<sub<1</sub<、<i<P</i<<sub<2</sub<、<i<P</i<<sub<3</sub< were established to make the legislation more suitable for China's real driving.