ObjectiveTo evaluate the clinical value of infrahyoid myocutaneous flap in the reconstruction of mouth floor tissue defects. MethodsInfrahyoid myocutaneous flap was made including stenohyoid,thyrohyoid,omohyoid and the affiliated skin based on the axis of superior thyroid artery,vein and ansa cervicalis. The clinical data of 11 patients with reconstruction of mouth floor tissue defects using infrahyoid myocutaneous flap (maximum area was 8 cm × 3 cm) from Match 1993 to June 2009 were retrospectively reviewed.ResultsSeven infrahyoid myocutaneous flaps which reserved platysma branch of superior thyroid artery were all alive, while 2 patients presented epidermal necrosis of 4 un-protected patients. The follow-up period was range from 24 months to 195 months, one patient received salvage surgery for local regional lymphatic recurrence in level Ⅰ,which survived without diseases until now.The rest cases had turned out a success.No dysphagia,dysphonia,and tongue extension difficulty was reported in any patient.ConclusionInfrahyoid myocutaneous flap is one of the valuable donor sites for the reconstruction of mouth floor tissue defects after radical oncologic operations,especially for those with early stage carcinoma of the mouth floor.