Objective To investigate the expression of regeneration gene protein2 (Reg-2) after the transection injury in rat spinal cord. Methods Forty five SD rats were randomly divided into two groups: in the injury group, the SCI was produced by complete transection of the cord at the 9th thoracic level, and the sham operation rats were taken as the normal control. The animals were perfused at 1h,1d,3d,7d,14d after the operation, and the spinal cord was taken out at different time points. The expressions of Reg-2 were tested by immunohistochemical analysis and Western blotting, the double staining of Reg-2 and different neural cells special markers(GFAP, Olig2，NPY，CGRP， GAP-43, et al)was done with immunofluorescence method. Results The expression of Reg-2 was found at 1h after the spinal cord injury, reached the peak on day 3 after the injury in the neurons of dorsal horn and day 7 in the neurons of ventral horn. The high expression persisted for 1 week, then decreased gradually.Conclusion Reg-2 may work as an important growth factor and participate in the regeneration and reha