Noise reduction capability of three difference kinds of porous materials i.e. rice husk, wood shavings and account fiber have been studied. Source of single frequency and multi-frequencies noise at intensity level of 90 dB(A) were carried out in the experiment. Difference in capability of noise reduction, in term of transmission and absorption, due to their intrinsic characteristic were obtained. Transmission capability of porous material at equal thickness varied inversely with the noise frequency, but absorption capability depend proportionally on frequency of sound. At frequency 1000 to 2000 Hz, all of porous materials of equal thickness, showed the peak of transmission due to their resonant behaviour. Exponentially decay of transmission coefficient and exponentially growth of absorption coefficient related with increasing thickness were obtained. But at frequency 1000 to 2000 Hz of increasing thickness porous materials, their noise reduction behaviour still showed resonant charateristics and did not follow the exponential model. Noise reduction efficiency of rice husk, wood shavings and coconut fiber at 5 cm thickness and 60 cm apart from noise source are 98.56, 96.39 and and 37.34 respectively. Noise reduction coefficient of them at specific frequency are 0.91, 0.89 and 0.46 respectively.