The　objective　of　this　paper　was　to　examine　the　feasibility　of　partial　nitrification　from　raw　domestic　wastewater　at　ambient　temperature　by　aeration　control　only.　Airflow　rate　was　selected　as　the　sole　operational　parameter.　A　14L　sequencing　batch　reactor　was　operated　at　23　degrees　C　for　8　months,　with　an　input　of　domestic　wastewater.　There　was　a　programmed　decrease　of　the　airflow　rate　to　28L.h(-1),　the　corresponding　average　dissolved　oxygen　(DO)　was　0.32mg.L-1,　and　the　average　nitrite　accumulation　rate　increased　to　92.4%　in　3　weeks.　Subsequently,　further　increase　in　the　airflow　rate　to　48L.h(-1)　did　not　destroy　the　partial　nitrification　to　nitrite,　with　average　DO　of　0.60mg.L-1　and　nitrite　accumulating　rate　of　95.6%.　The　results　showed　that　limited　airflow　rate　to　cause　oxygen　deficiency　in　the　reactor　would　eventually　induce　only　nitrification　to　nitrite　and　not　further　to　nitrate　and　that　this　system　showed　relatively　stability　at　higher　airflow　rate　independent　of　pH　and　temperature.　About　50%　of　influent　total　nitrogen　was　eliminated　coupling　with　partial　nitrification,　taking　the　advantage　of　low　DO　during　the　reaction.