The authors report 18 cases of the squamous cell carcinoma in floor of mouth with preoperative and postoperative findings and surgical methods who had been treated in Pusan Paik Hospital from Jan. 1986 to Sept. 1988. The results were as follows; 1) In the sex distribution, 16 cases(88.9%) were male and 2 cases(11.1%) were female. So the male was predominant. And the age distribution was from 45 to 72 years old and the mean age was 58 years old. 2) The distributions of involved sites were as follows; There were 5 case(27.7%) of midline, 3 cases(16.7%) of anterior part, 7 cases(38.9%) of posterior part and 3 cases(16.7%) of combined midline and anterior part. 3) The distributions of clinical stages were 2 cases(11.1%) of stage I, 3 cases(16.7%) of II, 7 cases(38.9%) of III and 6 cases(33.3%) of IV. 4) The methods of treatment were as follows; There were 1 case(5.6%) of operation only, 3 cases(16.7%) of operation with preoperative chemotherapy, 6 cases(33.3%) of operation with preoperative chemotherapy and postoperative radiotherapy. 5) In methods of the skin incision, 4 cases of lip splitting with chin splitting and 13 cases of lip splitting with chin sparing incisions were performed, and 1 case(5.6%) was not performed. 6) In the managaments of the mandible, there were 9 cases(50.0%) of mandibulotomy, 2 cases(11.1%) of marginal mandibulectomy, 4 cases(22.2%) of segmental mandibulectomy and 2 cases(11.1%) of hemimandibulectomy, and 1 case(5.5%) was not managed the mandible. 7) The neck dissections were as follows ; There were 5 cases(27.8%) of ipsilateral supraomohyoid neck dissection, 3 cases(16.7%) of lipsilateral radical neck dissection, 4 cases(22.2%) of ipsilateral radical neck dissection and contralateral supraomohyoid neck dissection and 2 cases (11.1%) of bilateral radical neck dissection, and 4 cases were not performed. 8) In the reconstructions, we used 2 cases of sternocleidomastoid myocutaneous flaps, 6 cases of pectoralis major myocutaneous flaps, 1 case of pectoralis major myocutaneous flap with Kirschner wire, 1 case of nape of neck flap, 3 cases of tonge flaps, 3 cases of skin gragfs and 2 cases of primary suture. 9) In the blood losses during operation, 3 cases(16.7%) of below 2,000cc 3 cases(16.7%) of 200-400cc, 8 cases(44.5%) of 400-800cc, 2 cases(11.1%) of 800-1,000cc, 1 case(5.6%) of 1,000-1,200cc and 1 case(5.6%) of 1,200-1,500cc were noted. 10) In the postoperative complications, there were 4 cases(17.3%) of orocutaneous fistula, 5 cases(21.7%) of disarticulation, 2 cases(8.8%) of facial palsy, 1 case(4.3%) of swallowing difficulty, 2 cases(8.8%) of skin contracture, 5 cases(21.7%) of malocclusion, 2 cases(8.8%) of facial edema, 1 case(4.3%) of headache and 1 case(4.3%) of limitation of month opening.