Abstract: In-vessel system was used to compost chicken manure, and mature chicken manure compost was applied as the media of biofilter to study the removal of odor emission. The composting reactor was made from an iron drum which had a cubage of 60L. The odor from the composting system passed through the three biofilters from their bottoms. Biofilter was made from a PVC tube which was 1 m high and had an inner diameter of 11 cm. In order to gain the optimal operating parameters of biofilter, and the authors seleced the assemblage, height, initial moisture content of the media and air detention time of biofilter to study. And what’s more, the property change of biofilter media during processing odor and the removal of Volatile Organic Compounds (VOCs) from chicken manure composting was studied. According to the experimental data, the optimal operating parameters of biofilter resulted in using matured chicken manure compost as biofilter media and bark as assistant material, media height of 50 cm, initial moisture content of 50% and 90.0 s of the detention time, respectively. The experimental results indicate that biofilter removes VOCs efficiently, the compounds categories and the concentration of VOCs reduce after being treated by biofilter. The comparison of ammonia and VOCs content shows ammonia takes a great proportion of 98.70% in the odor from chicken manure in-vessel composting, which indicates the concentration of ammonia could be employed to express the concentration of odor in this technics. The biofilter achieved a good removal efficiency of odor from chicken manure composting with matured chicken manure compost as biofilter media and bark as assistant material, which can promote biofilter utilization in chicken manure composting.