Abstract In order to utilize melt-textured YBa 2Cu 3O X superconductors in conductor applications, both the size of the oriented domains and the alignment of the grains have to be improved. A seeded directional solidification method has been developed to accomplish this goal. Due to the presence of the seed, single-domained bulk samples with preferential grain alignment have been obtained. Since the plate-shaped grains are aligned along the sample axis, the current capacity of these seeded superconductors are found to be insensitive to thermal cycling. In addition, the magnetic field dependency of critical current density in these long seeded superconductors is found to be in excellent agreement with that of well-textured short specimens.