Ho 3+ /Yb 3+ co-doped PbTiO 3 nanocrystals with different content of dopant were successfully prepared via a facile hydrothermal method. The purity, morphology, element distribution, chemical state and up-conversion (UC) photoluminescence (PL) of PbTiO 3 nanocrystals affected by Ho 3+ dopant are investigated systematically. X-ray diffraction (XRD) results illustrate that PbTiO 3 samples with the doping Ho 3+ concentration ranging from 0 to 5 mol-% are perovskite structure. The doping Ho 3+ ions have no change on the crystal structure of perovskite PbTiO 3 . Owing to the non-equivalent substitution of Ho 3+ to Ti 4+ in PbTiO 3 , the particle size of Ho 3+ /Yb 3+ co-doped PbTiO 3 samples is decreased as well as the particle agglomeration is detected.