【Abstract】 Objective To explore the features of Ki-ras mutations at codon 12 in Chinese patients of pancreatic cancer and to compare these features with those in Western countries. Methods Fifty-nine samples were collected during operations for pancreatic adenocarcinoma in our hospital from December 1989 to November 1997. The patients, age ranged from 30 to 73 years 〔(55.5±10.4) years〕,with 38 males and 21 female. TNM staging of the patients: stage Ⅰ(n=4); stage Ⅱ(n=8), stage Ⅲ(n=42),stage Ⅳ(n=5). PCR was used to amplify target gene and Dot blot hybridization for detecting Ki-ras mutations at codon 12 was performed in fifty-nine specimens of Chinese pancreatic cancer. The data of Ki-ras mutations at codon 12 from Western countries were gotten by Medline system. Results Ki-ras mutation at codon 12 was detected in 76.3% of the patients in this group. The frequency of double mutation of Ki-ras at codon 12 in this group (15.6%) was highest than that in western countries. Our results were compared with those reported in Western countries. The results suggested that there were the significant differences in the substitution of Ki-ras mutations at codon 12 and in the ratio of transition to transversion in pancreatic cancer among various countries. Conclusion Ki-ras mutations at codon 12 is frequent in Chinese pancreatic cancer, and a gene component to pancreatic cancer may be different among various countries. In addition, the effect of Ki-ras mutations at codon 12 on prognosis of patients with pancreatic cancer is different in various countries.