Abstract: The vibration characteristics of external mirrors are the important evaluation indicators of exterior rearview mirror, and its modal are an important factor which would affect the vibration performance of the glass on the car. In this paper, for the situation that the initial natural frequency of the exterior mirror of a passenger car doesn’t meet the design requirement, three optimized structures are proposed through the analysis of the structure, the simulation and test analysis. The results confirmed the three optimized structures were effective to avoid the risk of vibration of the exterior mirror in advance.