Abstract: The maturation of dendritic epidermal T lymphocytes (DETCs) in thymus needs ligand-mediated positive selection, and positive selection together with V3γ⁺ γδT lymphocytes intrinsic program features order DETCs to specifically migrate to epidermis. Positive selection promotes DETCs to express CD122, which is vital for DETCs to survive and proliferate in skin. DETCs possess memory-like phenotype and are able to rapidly respond to danger signals when they move out from thymus. NKG2D, junctional adhesion molecule-like protein and 2B4 are demonstrated to participate in DETCs activation, except for ligands of T lymphocytes receptor. Effective DETCs secrete cytokines such as interferon-γ, insulin-like growth factor-2, keratinocyte growth factor and gain cytotoxicity to directly kill tumor cells. DETCs participate in skin immune surveillance, regulation of local inflammation, and wound healing promotion.