In this work, La2O2S:Eu3+ nanophosphor was successfully synthesized through a combination method of co-precipitation andfollowing reduction step, using commercial available lanthanum sulfate octahydrate, europium nitrate hexahydrate andammonia water as experimental raw materials. Fourier transform infrared spectroscopy (FTIR) results showed that theprecursor contains OH and SO42 groups. X-ray diffraction (XRD) exhibited that the composition of the precursor isLa2(OH)4SO4·2H2O. After calcination at 800 oC in muffle furnace for 2 h, the precursor was transformed into the La2O2SO4phase and then reduced to pure La2O2S phase at 800 oC for 1h under a reducing atmosphere. Differential scanningcalorimetry/thermogravimetry (DSC/TG) analysis further confirmed that the removal of crystal water and dehydroxylationprocess from La2(OH)4SO4·2H2O to La2O2SO4. Field-emission scanning electron microscopy (FESEM) observations displayedthat the morphologies of La2(OH)4SO4·2H2O and La2O2SO4 are lamellar structures, while after reduction treatment, theproduced La2O2S possesses a rice ear-like shape with particle size of 20-50 nm. Photoluminescence (PL) spectra revealed thatthe La2O2S:Eu3+ nanophosphor displays excellent photoluminescent properties, with the main emission peak at 624 nm afterphotoexcitation at 254 nm, a good CIE coordinate of (0.6669, 0.3214), a short lifetime of 1.60 ms and an appropriate CCT valueof 3951 K.