With　the　deterioration　of　eutrophication　in　China,　nitrogen　and　phosphorus　removal　from　wastewater　have　caught　more　and　more　attention;　while　influent　C/P　ratio　is　one　of　the　most　important　influence　factors.　To　investigate　the　effects　of　feed　water　C/P　ratio　on　the　performance　of　anaerobic-anoxic-oxic　process,　four　different　feed　water　C/P　ratios　were　designed,　that　is　55,　45,　34,　23,　so　as　to　study　the　variations　of　COD,　TN,　PO43--P　and　sludge　characteristics　with　the　C/P　ratio.　The　results　showed　that　when　the　C/P　ratio　was　lower　than　32,　P　removal　efficiency　increased　as　C/P　ratio　increased　linearly,　while　the　C/P　ratio　was　higher　than　32,　the　P　removal　efficiency　maintained　at　90%-98%,　and　effluent　P　concentration　was　lower　than　0.5　mg　·　L-1.　In　contrast,　regardless　of　the　C/P　ratio,　excellent　COD　(90%)　and　good　total　nitrogen　removal　(75%-84%)　were　maintained　throughout　the　experiments.　However,　P　percentage　in　the　wasted　activated　sludge　(WAS)　increased　as　the　C/P　ratio　decreased.　It　was　also　found　that　denitrifying　P　removal　existed　under　different　C/P　ratios　by　controlling　the　operation,　and　nitrogen　and　phosphorus　removal　efficiency　could　be　improved.