Mn2+-doped phosphate glasses sensitized by Gd3+ ions are investigated. Enhanced photoluminescence (PL) properties of the samples are found with the excitations expanding toward the deep-UV part of the spectrum. PL emission and excitation spectra correlated with the lifetime data consistently present evidences of the enhanced Mn2+ emission in association with the energy transfer from Gd3+ ions. In particular, the Gd3+ codoping benefits greatly the energy harvesting of Mn2+ ions, resulting in the enhanced and tunable excitations of Mn2+ ions which expand toward the deep-UV part of the spectrum at 273 and 311nm, respectively. Thus by Gd3+ sensitizing, the excitation source of the Mn2+ emission has covered the broad range of the spectrum from the original blue and near-UVA to the deep-UVB and UVC together with the enhanced emission in the green-to-red spectral region. The possible energy-transfer mechanisms involved are discussed.