Calcium phosphate/calcium sulphate powders were synthesized by wet method. The effects of the initial calcium/phosphorus molar ratio and the pH of the solution on the microstructure and phase composition were studied by SEM, XRD, and FTIR spectroscopy. The results show that the pH value was the predominant parameter for the particle shape and the final phase composition of the calcined powders. (C) 2004 Elsevier B.V. All rights reserved.