Beta-tricalcium phosphate (beta-TCP) was obtained by calcining the precursor calcium deficient hydroxylapatite (CDHA). The CDHA was synthesized via direct precipitation method using calcium hrdroxide and phosphoric acid assisted with polyethylene glycol ((CH2CH2OH)(n); PEG). The X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential scanning calorimetry (TG/DSC), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to investigate the phase composition and morphology of obtained powders. The results showed that the PEG played an important role on improving the purity and dispersity of beta-TCP. The size of beta-TCP particles with nearly spherical shape was in the range of 0.2-0.5 mu m when the CH2CH2O/H+ molar ratio was equal to 1:17. According to the TG/DSC, the formation of the beta-TCP from the CDHA phase was about 770 degrees C. Meanwhile, a plausible synthetic mechanism has been proposed. (C) 2016 Elsevier B.V. All rights reserved.