The goals of lip reconstruction are to provide oral competence, adequate support for the lower lip, contour restoration, adequate lip sulcus, and adequate oral aperture. The composite radial forearm palmaris longus free flap is thin enough that it can be folded onto itself without a significant increase in bulk. The flap is easy to dissect, the pedicle contains long vessels of large diameter, and the skin is a good color and texture match for the perioral region. Moreover, the vascularized tendon can be used for lower lip reconstruction. This makes the flap ideally suited for total lower lip reconstruction. We experienced the case of total lower lip excision and reconstruction with the radial forearm free flap including palmaris longus tendon, so we reported that case with literature. The patient has a lower lip squamous carcinoma(T3NIM0), and performed a total lower lip excision with right modified radical neck dissection and left extended supraomohyoid neck dissection, and a reconstruction with radial forearm free flap includng palmaris longus tendon. The oral competence and masticatory function were nearly normalized and cosmetical result was very acceptable.