Ligation of the main excretory duct (MED) of the mouse submandibular gland (SMG) induced the expression of Sca-1, a stem cell marker. Sca-1 expression increased prominently in almost all of cells in the duct system, except the acinar cells. Sca-1 induction was accompanied with phosphorylated-STAT3 (Y705) elevation, which was localized in the nuclei of all duct cells. Electrophoretic mobility shift assay (EMSA) confirmed the specific binding of STAT3 to the GAS sequence, a biding site of gamma interferon activating site. Present study suggested one of the initial steps of the tissue regeneration after injury includes STAT3 pathway