This study was conducted to determine the odor reduction efficiency of a biofilter desist using different filter materials. The summary of results are as follows; 1. The airflow penetration rate of the different filter materials namely; rice straw, woodchips, rice hulls and sawdust were 0.72 m/s, 0.64 m/s, 0.48 m/s and 0.17 m/s, respectively. 2. The elimination of $NH_3$ gas was fastest in the rice hull at a rate of 4 mg/${iota}$ followed by sawdust, woodchips and rice straw at 3 mg/${iota}$, 3 mg/${iota}$ and 7 mg/${iota}$, respectively. 3. The filter material made of wood chips was able to eliminate the offensive gas known as $H_2S$ at a rate of 2.2 mg/${iota}$ on the 7th day, 17.6 mg/${iota}$ on the 21st day but decreased to 10.7 mg/${iota}$ on the 36th day. In contrast, the filter material composed of sawdust had a continuous increase in the reduction of $H_2S$ at a rate of 12.3 mg/${iota}$ on the 7th day, 18.3 mg/${iota}$ on the 21st day and 20.1 mg/${iota}$ on the 36th day. The above findings indicated that among the filter materials, sawdust was the most effective in absorbing $H_2S$. Airflow penetration rate can be related to $H_2S$ odor elimination efficiency as shown by the slowest airflow rate of sawdust which is only 0.17 m/s.