Single crystals of ferroelectric (Bi0.5Na0.5)TiO3 were successfully grown by using the top-seeded solution growth method at a high oxygen pressure of 0.9 MPa and their polarization switching dynamics along the 〈100〉c direction and their domain structures were investigated. Piezoelectric force microscope (PFM) observations show that BNT crystals poled along the 〈100〉c direction. had 71-degree domains in which the spontaneous polarization (Ps) vector was opposite to the direction of the poling electric field. Synchrotron-radiation single-crystal X-ray diffraction analyses and PFM observations revealed that the polarization switching in the BNT crystals along the 〈100〉c direction was achieved by a 71-degree rotation of the Ps vector.