In this research the characteristics of ammonia removal from malodorous waste-air were investigated under various operating condition of biofiilter packed with equal volume of rubber media and compost for the efficient removal of ammonia, representative source of malodor frequently generated at compost manufacturing factory and publicly owned facilities. Then the optimum conditions were constructed to treat waste-air containing ammonia with biofilter. Biofilter was run for 30 days(experimental frequency of 2 times/day makes 60 experimental times.) with the ammonia loading from 2.18 g-N/m3/h to 70 g-N/m3/h at 30 ℃. The ammonia removal efficiency reached almost 100% for I through IV stage of run to degrade up to the ammonia loading of 17 g-N/m3/h. However the removal efficiency dropped to 80% when ammonia loading increased to 35 g-N/m3/h, which makes the elimination capacity of ammonia 28 g-N/m3/h for V stage of run. However, the removal efficiency remained 80% and the maximum elimination capacity reached 55 g-N/m3/h when ammonia loading was doubled 70 g-N/m3/h for VI stage of run. Thus the maximum elimination capacity exceeded 1,200 g-N/m3/day(i.e., 50 g-N/m3/h) of the experiment of biofilter packed with rock wool inoculated with night soil sludge by Kim et al.. However, the critical loading did not exceed 810 g-N/m3/day (i.e., 33.75 g-N/m3/h) of the biofilter experiment by Kim et al.. The reason to exceed the maximum elimination capacity of Kim et al. may be attributed to that the rubber media used as biofilter packing material provide the better environment for the fixation of nitrifying and denitrification bacteria to its surface coated with coconut based-activated carbon powder and well-developed inner-pores, respectively.