Biochar　materials　are　good　reducers　of　nitrogen　oxides.　The　composition　and　structure　of　biochar　affect　significantly　its　ability　to　reduce　C-NO.　In　order　to　study　the　denitration　of　flue　gases　by　biochar　at　high　temperature,　three　kinds　of　biochar　(bamboo　charcoal　(BC),　rice　husk　ash　(RHA),　and　straw　charcoal　(SC))　were　mixed　with　cement　raw　meal　in　a　fixed-bed　quartz　reactor　at　the　temperature　of　800-900　degrees　C　and　O-2　concentration　of　0.5%-2%.　The　results　showed　that　the　initial　denitration　rate　of　BC　was　higher　than　that　of　RHA,　and　that　of　SC　was　the　lowest.　RHA　had　the　largest　specific　surface　area,　and　BC　the　smallest.　The　elements　C,　N,　and　O　and　the　functional　groups　of　the　three　types　of　biochar　had　a　greater　influence　on　the　denitration　rate　than　their　structures.　The　denitration　rate　decreased　faster　as　the　O/C　ratio　increased,　and　the　increase　in　the　relative　content　of　the　N　element　induced　the　formation　of　nitrogen-containing　functional　groups　catalyzing　C-NO　reduction.　The　content　of　the　C-C　bond　affected　directly　the　rate　of　denitration,　and　both　(NCO)(x)　and　C-O　bonds　had　a　positive　effect　on　the　reduction　capability　of　biochar.　It　can　be　concluded　that　the　composition　of　biochar　has　an　important　effect　on　the　reduction　of　C-NO.