Regarding to the pancreatic cancer, outcomes of the patients surgically treated have been poor. By using polymerase chain reaction (PCR), paraffin-embedded specimens of the pancreatic carcinoma were confined point mutation in Kirsten (K)-ras codon 12. Then, incidence and type of point mutation of this oncogene and correlative studies with stage, T or N factor of pancreatic cancer were analysed. Extremely high incidence of K-ras gene mutation was shown in present report. The highest mode of point mutation of K-ras oncogene was GGT to GAT coded aspartic acid. Cases without point mutation in K-ras codon 12 were significantly frequent in papillary adenocarcinoma than in tubular type. There were not correlative result among mutation types, stage and T factor of pancreatic cancer. Most patients with pancreatic cancer who survived more than 2 years have not shown mutation to aspartic acid. Four cases including two cases of mucin producing pancreatic cancer did not have point mutation in K-ras codon 12. Pathogenesis of mucin producing cancer can be distinguished from typical pancreatic cancer by detection of point mutation in K-ras codon 12 using PCR.