Abstract: As a composting conditioner，biochar plays an important role in speeding up process of livestock and poultry manure aerobic composting，enhancing quality of composting and improving composting technology.Corn straw and leaves were mixed with chicken manure for composting experiment.The influence of biochar on composting process was analyzed by studying changes of reactor temperature，water content，pH value，electrical conductivity and nutrient contents of nitrogen，phosphorus and potassium.Results showed that adding biochar could effectively shorten composting cycle by 2~3 d.In the early stage，adding biochar would increase pH value of pile body，but it had no significant effect on final composting product.The EC value of adding biochar was lower than that of not adding biochar，indicating that biochar had a good fixation effect on free salt ions.Through detection of main nutrients at each stage of heap material，contents of total nitrogen，total phosphorus and total potassium in biochar compost were higher than those in non-adding group.The total nitrogen content of MSA and LA increased by 0.35% and 0.53%，respectively，compared with MS and L，indicating that biochar had better nitrogen fixation effect.Comprehensive pH value，electrical conductivity，water content and other indicators，as a conditioner，biochar could promote aerobic fermentation process，which was conducive to improving quality of compost.