There are different parts which could reduce the vibration transmitting to vehicle body. Here, we will focus on Lower arm B (LAB) mounted on suspension which bears spring load and damper load. Former tests show that LAB will transmit much vibration to the cabin. In order to understand the transmit principle, we carried on a series of experiments and simulations on the LAB. In this paper, the modal test is improved further by using the pre-test analysis results, and then the FEA simulations of LAB is updated through modal test results. At last, the dynamic performance LAB is gained by experiments and simulations for further study in the sus-pension assembly. The results of the simulations and experiments are in good agreement.