CeVO4 nanocrystals doped by heteroions were prepared via a hydrothermal method without the presence of surfactants or templates. Transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), solid state V-51 NMR, and inductively coupled plasma (ICP) were used to characterize the morphology, structure, and compositions of the materials. X-ray photoelectron spectroscopy (XPS) results confirmed that there is a valence change from Ce3+ to Ce4+ for a fraction of cerium atoms whereas the vanadium atoms remain in the pentavalent state V5+ upon the substitution of Ca2+ into CeVO4. Raman spectroscopy was used to monitor the effects of the doping ion on the CeVO4 lattice contraction and distortion. The appearance of the shifted and broadened Raman peaks for the doped CeVO4 was interpreted by theoretical calculations performed with Vienna ab initio simulation package. The redox properties and photocatalytic activities of the obtained nanocrystals were also investigated and discussed in detail.