Electric-field and/or temperature induced phase transitions were observed using polarizing light microscope on -oriented Pb (Mg1/3Nb 2/3)O3-0.3PbTiO3(PMN-0.3PT) single crystals with electric fields applied along the  and  directions, respectively. The monoclinic (M) and tetragonal (T) phases were observed with electric field applied along the  direction at 5 and 9 kV/cm, respectively. The orthorhombic (O) and T were observed with 5 kV/cm and 10 kV/cm electric field applied along the  direction, respectively. The intermediate phases [M and/or O phase(s)] were also confirmed by the temperature-dependent dielectric behavior. © 2010 American Institute of Physics.