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This study aims to identify the effect of road surface contours on the fatigue life of a coil spring and a lower arm. In this study, strain gauges were installed at the critical points of the components based on stress distributions. According to the chemical composition tests, the coil spring was made from SAE 5160 and lower arm was made from AISI 1513. Strain signals obtained were analyzed using the Coffin-Manson, Morrow, and Smith-Watson-Topper models. Based on the strain signals, it was found that when the vehicle was driven on the rough road, coil spring and lower arm received higher stresses contributing to a shorter fatigue life. The fatigue life of the coil spring when was driven on the rough road was 7 % lower than when was driven on the smooth road. Meanwhile the fatigue life of the lower arm when was driven on the rough surface was only 0.03 % lower than when was driven on the smooth road. It indicated that the coil spring will fail faster than the lower arm. This is because the contour of the road surfaces provide a vertical load so that it is in accordance with the function of the coil spring which works to reduce the load vertically, while the lower arm functions to hold the load when turning.