The optimized conditions for phosphorus recovery as hydroxyapatite from wastewater by synthetic tobermorite through seeded crystallization were studied in this paper. The results show that pH value of 8, Ca/P ratio of 2 (molar ratio) and 1.6 g/L seed concentration seem to be the favorable conditions. It is proved that under the optimized conditions the seed can yield alkalis. During the process in which tobermorite was used for eighteen times, all the concentrations of residual phosphorus were satisfactory. Characteristics of the products weredetermined by such analytical techniques as Powder X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and EDS. The results show that the main recovered product is hydroxyapatite with a lower cryst allization degree.