A batch composting study was performed to evaluate effects of biochar addition on dynamics of microbial community and changes of key physic-chemical properties during composting of tomato stalk and chicken manure. As a comparison, two amendments of peat bog and zeolite were selected. The results indicated that biochar addition for composting showed a shorter time to enter thermophilic phase (3 d) and a higher temperature (56 degrees C) and longer duration of thermophilic phase compared to that of peat bog addition, zeolite addition and raw composts. The highest C/N ratio and volatile fatty acids' concentration with biochar addition were obtained. Biochar addition also showed more influence on bacterial community changes than that of peat bog and zeolite. Thus, biochar addition could significantly affect physic-chemical process and microbial community diversity on tomato stalk and chicken manure composting. This study provides valuable information for improving composting and a better understanding of biodegradation processes. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.