Single crystal superalloys have been prepared by adopting the grain selector and seeding technique in a high temperature gradient directional solidification furnace. The orientation characteristics were measured by XRD. Results indicated that for the grain selector method, the crystal solidification began at the cooling plate with random nucleation, and through mutual competitive growth at the starter block. The grains entered the spiral selector, and finally the single crystal superalloys which were close to <001> direction were obtained. By using the seeding technique, by epitaxial growth of partially melted seed crystals, single crystal superalloys which have the same orientation as the seed crystal were obtained.