Variation of bioavailable phosphorus ( BAP )concentrations,i.e.,the sum of dissolved total phosphorus (DTP)and bioavailable particulate phosphorus ( BAPP),was investigated in a phosphorus (P)-abundant system as influenced by repeated sediment resuspension.The overlying water and sediments in the studied system collected from a city canal,with the initial BAP concentration about 0.679 mg · L -1 in the overlying water.The sediments were disturbed with rotating blade once every day for 30 days in the experimental system. Concentrations of dissolved inorganic phosphorus ( DIP),DTP,and total phosphorus (TP) in overlying water and algal available phosphorus (AAP),total phosphorus (Tot-P) in suspended particles were determined in diminishing frequency.It was found that the BAP decreased rapidly in the beginning few days in the sediment resuspension system,and then kept decreasing gradually at a low level,compared with the static conditions.This was mainly attributed to the sharp decrease of DIP.It is suggested that repeated sediment resuspension plays a significant role in phosphorus migration and converting it to more stable forms.