The crystal structure of K 2 Zn͑PO 3 ͒ 4 was determined and refined using the Rietveld method based on the isostructure model of K 2 Cu͑PO 3 ͒ 4 . This compound belongs to the monoclinic system with space group Cc and lattice parameters of a = 11.0941͑2͒ Å, b = 12.5215͑3͒ Å, c = 7.6597͑2͒ Å, and  = 102.47͑2͒°. The chemical formula unit per unit cell is Z = 4 and the calculated density is 2.938͑3͒ g / cm 3 . Zigzag ͓PO 3 ͔ ϱ chains formed along the a axis, and their period contains eight PO 4 tetrahedrons.