The Er3+-activated LaBMoO6 phosphors were synthesized by a sol-gel method. The photoluminescence (PL) emission intensity was revealed to be dependent on the Er3+ ion concentration and its maximum value was achieved when the doping concentration was 1 mol%. From theoretical analysis, one knows that the concentration quenching mechanism is dominated by the electric dipole-dipole interaction with a critical distance of 28.47 angstrom. On the basis of the temperature-dependent PL green emission spectra from the H-2(1) (1/)(2) and S-4(3/2) thermally coupled levels by means of the fluorescence intensity ratio technique, the temperature sensing properties of the resultant compounds were studied. When the temperature was 483 K, the sensor sensitivity of the studied samples reached up to 0.017 K-1. It was found that the sensor sensitivity of the prepared phosphors was hardly varied by the doping concentration. These obtained characteristics suggest that the Er3+ -activated LaBMoO6 phosphors have potential applications in optical thermometry.