Oral squamous carcinoma can be divided into tongue cancer, gum cancer, buccal mucosa cancer, palate cancer, floor of mouth cancer, etc. Early symptoms can be infiltration to surrounding tissues or ulcerative type, as follows. 1. Tongue cancer: it can be infiltrative or ulcerative, with fast growth and strong infiltrative, which can affect tongue muscle, limiting tongue movement and affecting speech, feeding and swallowing. 2. Gingival cancer: gingival cancer is more common in ulcerative type, which infiltrates into alveolar process and jawbone at early stage, destroys bone quality and causes loosening of teeth and pain. 3. Buccal mucosa cancer: it often occurs near the molar area, with ulcerative or exophytic type, growing fast and infiltrating into the deep layer. 4. Palate cancer: it develops slowly and can invade the bone of palate and cause palate perforation. 5. Cancer of the floor of the mouth: it is often ulcerated in the early stage and may have pain, accompanied by increased saliva. If the above symptoms appear, it is recommended to go to the hospital for consultation and early professional treatment.