We investigated the effect of chemoradiotherapy(CRT)on pancreatic cancer and the significance of preoperative chemoradiotherapy( NACRT)on resectable pancreatic cancer. The subjects were 36 patients who underwent CRT for locally advanced pancreatic cancer experienced in our department in the past 12 years(. 1)Regarding the antitumor effect of CRT, tumor diameter, tumor marker, and FDG for PET examination were reduced in 72%, 81%, and 96% of cases, respectively. In addition, the effect of Grade 1b plus 2 was observed in 10 of 16 patients who were resected after CRT(response rate 63%). In these successful cases, irradiation of 40 Gy or more and oral administration of S-1 1,500 mg or more were performed during this period. In addition, the survival rate of the NACRT plus S group(16 cases)was the same as that of the SF group (20 cases)of cStage ⅡA or lower at the same time, 50% survival was longer, and local recurrence was less. Based on the above, preoperative chemoradiotherapy combined with S-1 for resectable pancreatic cancer may be a promising preoperative treatment in the future.