New ferroelectric crystals Pb(Er1/2Nb1/2)-Pb(Mg1/3Nb1/3)O-PbTiO3 (PEN-PMN-PT) were grown by using the flux method. Phase structure of the crystals was described by the X-ray diffraction analysis. Dielectric, ferroelectric and optical properties of the PEN-PMN-PT crystals were investigated systematically. Higher Curie temperature (Tc ~ 291 °C) and larger coercive field (Ec ~ 17.6 kV/cm) for the 40PEN-13PMN-47PT can be obtained, respectively, compared with those of the PMN-PT. Moreover, strong green and red emissions can be excited by using the 980 nm laser. The PEN-PMN-PT crystals with these performances have some promising applications in the electromechanical and optical devices.