A fire proofing sound absorbing material were prepared using light ceramsite, cement as main raw materials. The expanded perlite, polypropylene fibers and foaming agent were added to raise the porosity of the ceramsite concrete. The influences of these three sound absorbing materials on the absorbing characteristics were investigated. The results show that these three kinds of raw materials can enhance the sound absorbing properties of the samples. It is also found that the polypropylene fiber can improve the strength of materials, on the contrary, expanded perlite and foaming agent can significantly reduce the strength. The relationship of porosity and sound absorption of the sound absorbing materials in different frequency band are established by the micro analysis of SEM photos.