Possibility of grain orientation controlling by thermal diffusion treatment at various temperature gradient was studied for the superconductive YBa₂Cu₃O_y ceramics by means of X-ray diffraction analysis and SEM observations: The degree of orientation estimated by X-ray diffraction analysis was unexpectedly low, but local structures in SEM images was observed to be fairly oriented along heat flow derections. For obtaining highly oriented structures, one-directional temperature gradient during sintering should be elevated as possible.