This paper introduces the experimental analysis of the resonator in the rolling piston type compressor for air conditioner. The resonator located between cylinder and hearing is a major factor in the noise reduction of the rotary compressor. Several shapes for the resonator which can be built in the space limitations are derived. Then optimal resonator type for the noise reduction is determined by noise tests. 6 design parameters of the type are found and optimal level for each design factor is deduced from Taguchi method.