The synthesis and characterization of anhydorus Mg-3(PO4)(2) was investigated. Mg-3(PO4)(2) is reported to have similar structural arrangements with Co-3(PO4)(2) and gamma-Zn-3(PO4)(2) compounds. The sample was prepared by a new technique which is the reaction of MgCl2 . 6H(2)O and Na3PO4 . 12H(2)O solutions at pH=5.1, which was adjusted by adding concentrated H3PO4 to the reaction mixture and heating the precipitated product at 600 degrees C untill constant weight. The purity of the product was checked by X-ray powder diffraction, IR, density measurement, SEM and DTA analysis. The monoclinic unit cell. dimensions of product are a=7.605 (2), b=8.233 (3), c=5.080 (1)Angstrom degrees and beta=94.19 degrees (3), which was in good agreement with the reported data for Mg-3(PO4)(2). In the IR spectra, peaks due to PO4 anion of T-d symmetry split because of the monoclinic crystal structure with the space group of P2(1)/m. The SEM micrographs showed a spongy appearance with cavities. DTA analysis proved that anhydrous Mg-3(PO4)(2) is stable up to melting point which is 1184 degrees C.