The influence of temperature on electric-field-induced domain switching of [0 0 1]c oriented 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 (PMN–0.3PT) single crystal has been studied. The piezoelectric properties of PMN–0.3PT single crystal change drastically at one critical field at 30 °C and two critical fields at 90 °C corresponding to electric-field-induced domain switching. The domain structures were studied by polarizing light microscopy on the [100]c surface under the electric field applied along [001]c direction. The PMN–0.3PT single crystal exhibits a rapid increase in piezoresponse at 100 V/mm, which is related to R–MA phase transformation. At 90°C, the M and T0 0 1 phases coexist at 100 V/mm, while T001 mono-domain appears at 300 V/mm. The domain switching process here can be identified as (T100 or T010) → M → T001. The experimental results show that the phase state and domain structures of the crystal are closely related to the piezoelectric behaviors.