Er3+/Yb3+ /Li+ /Zn2+:Gd2O3 nanophosphors synthesized via combustion synthesis method have been structurally and optically characterized. The average particles size of the developed nanophosphors has been found to be similar to 25 nm by Transmission Electron Microscopy (TEM) analysis which is in good agreement with the X-rays Diffraction (XRD) results. The significant enhancement in upconversion (UC) emission intensity for green (similar to 20 and 70 times) and red (similar to 7 and 20 times) band have been observed after codoping with Li+ and Zn2+ ions respectively in Er3+-Yb3+:Gd2O3 system. The temperature sensing capability of the optimized nanophosphors has been studied corresponding to two thermally coupled H-2(11/2) and S-4(3/2) levels of the Er3+ ions. The sensitivity similar to 0.0096 K-1, 0.00109 K-1 and 0.0116 K-1 have been reported in the Er3+-Yb3+:Gd2O3, Er3+-Yb3+- Li+:Gd2O3 and Er3+-Yb3+-Zn2+:Gd2O3 nanophosphors respectively. The photometric characterizations of the developed nanophosphors have also been reported.