Hexagonal LnPO(4) (Ln = La, Ce) nanorods and monoclinic LnPO(4) (Ln = La, Ce) nanospheroids (NSPs) were synthesized by hydrothermal methods Au/LnPO(4) catalysts were prepared by a modified deposition-precipitation method. The samples were characterized by N-2 adsorption-desorption, ICP, XRD, TEM, EDX, XPS, and CO2-TPD. The catalytic tests for CO oxidation demonstrated that morphologies of LnPO(4) would influence the activity of Au/LnPO4. 1.0% Au/LaPO4-NRs catalyst exhibited best catalytic activity achieving complete CO conversion at 25 degrees C among Au/LnPO(4) catalysts. The sintering resistance of gold nanoparticles in Au/LnPO(4) upon calcination was enhanced due to the strong metal-support interaction. Au/LnPO(4) also showed good stability for CO oxidation with no deactivation after continuous operation for 10 h. The possible mechanism of CO oxidation on Au/LnPO(4) catalysts was also briefly described.