©　2017,　Editorial　Department　of　Chinese　Society　of　Power　Engineering.　All　right　reserved.To　optimize　the　NOx　removal　system　by　selective　non-catalytic　reduction　(SNCR)　and　to　control　the　NOx　emission　in　power　plants,　an　isothermal　SNCR　experimental　setup　was　established　to　study　the　effects　of　following　factors　on　the　SNCR　process,　such　as　the　reaction　temperature,　mixing　time　and　O2　concentration,　etc.　Results　show　that,　in　the　temperature　range　of　973-1　373　K,　with　the　rise　of　reaction　temperature,　the　NOx　removal　efficiency　first　increases　and　then　decreases,　and　the　optimum　denitrification　temperature　is　1　173　K,　when　the　removal　efficiency　could　reach　92.　9%.　The　efficiency　of　NOx　removal　can　be　effectively　improved　by　reducing　the　mixing　time,　especially　when　the　temperature　is　higher　than　1　203　K.　The　efficiency　of　NOx　removal　increases　with　rising　O2　concentration　at　the　temperature　lower　than　1　148　K,　while　decreases　at　the　temperature　higher　than　1　148　K.