Yb3+/Tm3+ co-doped BaGd2ZnO5 phosphors have been effectively synthesized by traditional sol-gel method. The graph of X-ray diffraction (XRD) exhibited that the obtained phosphors were pure orthorhombic phase. The morphology and composition of the samples were obtained by field emission-scanning electron microscope (FE-SEM) and the energy dispersive spectrometry (EDS). From upconversion luminance (UCL) emission spectra, the two strong blue emissions were obviously observed at 478 and 485 nm under the excitation of 980 nm. The possible energy diagram and UC mechanism were explained in detail. Optical temperature (T) sensing performances were evaluated in the temperature ranging 313 K - 573 K. And the highest sensor sensitivity calculated was 0.0055 K-1 at 323 K. Additionally, the laser excitation heating effect was also explored. The results indicated that Yb3+/Tm3+ co-doped BaGd2ZnO5 phosphors could be applied on optical temperature sensors and optical heater. (C) 2016 Elsevier B.V. All rights reserved.