By using polyol synthesis Yb3+/Ho3+ co-doped CePO4nanophosphors were prepared which appear both up-conversion (UC) and down-conversion (DC) with excellent luminescence properties. DC peaks were observed at ∼460, ∼550, ∼650, and ∼750 nm, at 300 nm excitation. A very weak P-O Charge Transfer(CT) band of Ho3+ionsis observed. We discovered that CePO4: Yb3+/Ho3+, anup-conversion (UC) nano phosphor also observed. At strong 980 nm laser illumination, the up-conversion emission spectra show a visible expectant peak of the Ho3+ ion at ∼550 and ∼650 nm. This process yields high-quality nanocrystal materials with sizes between the tens of nm range. Considering the results of the study at 300nm excitation, CePO4: Yb3+/Ho3+ produced a high quantum yield value. These findings are useful for making highly efficient phosphors, and it demonstrates the many applications of the nanophosphor materials covered by this approach.