In this paper, the reaching laws in the sliding mode control (SMC) will be evaluated. The reaching laws include the constant rate reaching law, the exponential reaching law, and the power rate reaching law. A mass spring damper system (MSD) is chosen to test and evaluate the performance of the proposed controller. The MSD system has been applied in most dynamic suspension systems to provide more reliability of the design requirements such as increasing the factors of safety or absorbing the impact forces. The SMC based on the reaching laws will be designed to guarantee the real position of the MSD system following the reference. Simulation results in MATLAB/Simulink show that the SMC provides better performance than the traditional PID controller, and the SMC based on the exponential reaching law is suitable to control the MSD system with the overshoot is about 0.154(%), the steady-state error is eliminated, the settling time is 0.4043(s), and the rising time achieves 0.2248(s).