How　to　effectively　improve　A/O　process　nitrogen　removal　efficiency　is　always　a　concerned　problem.　Nitrogen　removal　influence　factors;　DO,　internal　recirculaiton　flow　rate,　sludge　recycle　flow　rate,　SRT,　influent　COD/TN　and　HRT,　were　clearly　studied　using　starch　wastewater,　and　corresponding　control　strategies　were　established,　such　as,　using　effluent　ammonia　concentration　control　DO;　using　nitrate　concentration　at　the　end　of　anoxic　zone　control　internal　recirculation　flow　rate;　using　influent　COD/TN　or　effluent　total　nitrogen　concentration　control　external　carbon　dose　rate.　Based　on　the　above　analysis,　improving　A/O　nitrification　and　denitrification　rate　expert　control　system　was　established.