To examine the correlationship between IR attenuation and physical properties of suspended particles, IR spectrometer can be used effectively. Several graphite flakes and metallic powders were suspend-ed in a liquid cell and the IR attenuations were measured. The results were analyzed in terms of their physical properties such as shape, purity and more developed flake type showed higher IR attenuation. JG02 and BR06 showed the highest mass and volume extinction coefficient, α=1.14m²/ｇ, β= 2.7m²/cm³, respectively. This technique was considered as more efficient method than the conventional one using aerosol chamber. It could reduce the error caused by external factors and was even more simple to measure the physical effects of various kinds of suspended powders.