In order to compare the value of polymerase chain reaction(PCR)with 14 C urea breath test( 14 C UBT)for the diagnosis of Helicobacter pylori (Hp),specimens from 66 patients with upper gastrointestinal diseases were detected by both methods.The results showed the sensitivity of the PCR and 14 C UBT for the diagnosis of Hp infection were all 100%,the specificity were 95 2% and 90 5%,and the accuracy were 98 5% and 97 0%,respectively.There were not statistically significant difference between PCR and 14 C UBT,and also between males and females.This study shows that 14 C UBT and PCR assay with selfmade sampling tool for collecting gastric secretion have the advantages of being noninvasive,simple,high sensitivity and specificity.The latter can be used to discriminate cytotoxic strains with no cytotoxic strains of Hp,and that conquer the shortages of 14 C UBT being radioactive and using poisonous reagents.PCR assay is recommendable to apply for the diagnosis of Hp infection.