Intensity parameters Ωλ(or τλ) of Er3+ in crystal ErP5O14 were calculated by Judd-Ofelt theory. With these Ωλ valus, the oscillator strength, spontaneous radiative transition rate,seadiative lifetime, branching ratio and integrated emission cross section were calculated. In comparison with integrated emission cross section of certain laser crystals such as YAlO3:Er3+ and-CaF2:Er3+, the potential application of ErP5O14 as laser material was discussed.