We characterized the physical and chemical properties of various media (hardwood mulch, softwood mulch and composts) for livestock air pollutants degradation biofilters. Density, porosity, pH, total carbon, total nitrogen, organic matter content, particle size distribution and airflow resistance of each medium material were tested by using standard methods. Airflow resistance of each media was tested in a 0.61mx0.98mx0.61m testing chamber and the results were fitted into Hukill and Ives (1955) equation. It was found that particle size, moisture content, and compaction of media have significant effects on airflow resistance. Quantification of air pollutants removal capability with selected media will be conducted on laboratory/pilot scale biofilters later. This research aims to provide a database of effective, low cost and easily available media for biofilter design in the Midwestern US.