In this work, spherical Na(La,RE)(MoO[Formula: see text] (RE = Eu/Yb-Er) double molybdates were prepared using the rare earth hydroxide (La,RE)(OH)SO4 as a self-sacrificing template. The composition, structure, morphology, up/down conversion luminescence and fluorescence lifetime (FL) of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence spectrophotometer, and Fourier transform infrared (FT-IR) spectrophotometer. The results indicate that highly pure spherical Na(La,RE)(MoO[Formula: see text] (RE = Eu/Yb-Er) samples can be obtained from the proposed route. The room temperature and temperature-dependent up/down conversion luminescence properties of the resulting Na(La,RE)(MoO[Formula: see text] (RE = Eu/Yb-Er) phosphors were analyzed in detail. The temperature-sensing performances for the two phosphors in both fluorescence intensity ratio (FIR) and FL modes were evaluated. Classical down and up-conversion photoluminescence (PL) from Eu[Formula: see text] and Er[Formula: see text] were observed. The down conversion phosphors were proved to be capable of sensing temperature via FL mode, and the maximum absolute sensitivity (SA) and maximum relative sensitivity (SR) were found to be [Formula: see text][Formula: see text]K[Formula: see text] (298[Formula: see text]K) and [Formula: see text][Formula: see text]K[Formula: see text] (523[Formula: see text]K), respectively. The up conversion phosphors Na(La,Yb,Er)(MoO[Formula: see text] were well capable of sensing temperature via FIR mode through thermally coupled 2H[Formula: see text], 4S[Formula: see text] levels (I[Formula: see text]/I[Formula: see text], and the maximum absolute sensitivity (SA) and maximum relative sensitivity (SR) were found to be [Formula: see text][Formula: see text]K[Formula: see text] (523[Formula: see text]K) and [Formula: see text][Formula: see text]K[Formula: see text] (348[Formula: see text]K), respectively.