Feasibility test for a biofilter was performed to treat VOCs. The applied loading rate to the biofilter was calculated between 60 to $3,700;kg;COD/m^3$. Trimethyl-pentene and trimethyl-hexene were the two most dominant compounds and they occupy about 85 percent. During the acclimation period, it is desirable for a biofilter to receive relatively lower VOCs concentration and flow rate, until it can adjust to new substrate and operational environment. Temperature at various points inside the biofilter reactor was observed with more than 23 temperature sensors. With steam heating, temperatures of the top sections of the media were greater than those of bottom sections. Without steam heating, intermediate stages generally had higher temperature measurement than those of bottom and top stages. Because the pH values for different biofilter materials vary significantly, measurement of the pH for the mixture of different combinations of biofilter materials is necessary. Based on the types and brands of media, the measured pH ranged from 5.38 to 9.10. The range of measured pH of different mixtures with perlite, compost, saw dust, peat moss, limestone, vermiculite was 7.05 to 8.62.