Hydrothermal treatment of nanoscale amorphous ceric phosphate gel in KOH aqueous solutions was found to result in a new KCe 2 (PO 4 ) 3 phase. The refinement of the KCe 2 (PO 4 ) 3 structure showed that it was isostructural to recently reported (NH 4 )Ce 2 (PO 4 ) 3 . For the KCe 2 (PO 4 ) 3 phase, the unit cell parameters (sp. gr. C2/c) were a = 17.3781(3) Å, b = 6.7287(1) Å, c = 7.9711(2) Å, β = 102.351(1) • , V = 910.53(4) Å3 , Z = 4. The thermal decomposition of KCe 2 (PO 4 ) 3 at 800 • C resulted in the mixture of crystalline CePO 4 and KPO 3 .