To perform Modal analysis on Muffler guard to find the Natural frequencies and mode shapes. : Suction muffler is one of the important components of a compressor for low noise level and high efficiency. The suction muffler which has the complicated flow path gives the higher transmission loss of sound, but lower efficiency of compressor results from the superheating effect and flow loss in suction flow path. It is shown that the computational analyses of fluid dynamics are very popular methods for designing of high performance and low noise suction muffler. To reduce the thermodynamic and flow loss in suction process, the flow path of suction muffler was estimated by FVM (Finite Volume Method) and verified by experiments. And to enlarge the transmission loss of sound, the acoustic properties inside the suction muffler was analyzed by FEM (Finite Element Method) and experiments. The smart muffler which gives a good efficiency and low noise character was developed by using those methods, and the effect was evaluated in compressor by experiment.