Effects　of　phosphorus　removal　by　three　kinds　of　composite　polyaluminum　chloride　(PAC)　in　laboratory　scale　are　compared　in　this　article.　Relations　between　phosphorus　removal　and　turbidity　removal　by　coagulation　are　investigated.　Effects　of　water　temperature　and　pH　value　to　phosphorus　removal　are　observed,　and　removal　effects　of　various　phosphorus　formations　by　coagulation　are　reviewed.　Effects　of　phosphorus　removal　are　further　studied　by　combined　applications　of　PAC　and　polyacrylamide　(PAM).　The　results　showed　that　the　No.3　PAC　is　the　most　effective　one,　and　effects　of　phosphorus　removal　of　drinking　water　treatment　can　be　clearly　improved　by　enhanced　coagulation.　The　optimum　pH　value　of　phosphorus　removal　is　7.　Effects　of　phosphorus　removal　can　be　improved　by　raising　water　temperature.　In　general,　it　is　more　difficult　to　remove　dissolved　phosphorus,　but　phosphate　can　be　effectively　removed　by　dosing　more　coagulant.　The　effects　of　phosphorus　removal　by　coagulation　aid　can　be　achieved　more　effectively　by　adding　PAM　after　five　minutes　medium　rate　mixing　during　coagulation,　with　the　optimum　dosage　of　0.7　mg/L.