Abstract: Objective Developing a method to detect the transplanted cells in rat brains. Methods A SRY gene probe on rat Y chromosomes was cloned and labeled. The probe was used in situ hybridzation (ISH) on female rat brains. Results The experiments showed that the probe of SRY gene could catch the male-derived cells exactly in female brains. Conclution Using ISH of male-derived probe can trace the transplanted cells in female rats.