Recently, dental plaque (DP) and saliva have been implicated as possible sources of Helicobacter pylori infection. This subject was studied to investigate the detection rates of H. pylori in the DP and saliva by use of EIA, CLO tests and culture depending on H. pylori infection state of gastric mucosa. H. pylori positive was found in 68.3% (468) by CLO test, 46.4% (318) by EIA and 43% (295) by culture in gastric mucosa samples taken from 685 patients. CLO positive of 468 patients in dental plaque is found from dentate patients 11.1%, edentulous patients 16.23% and saliva from dentate patients 2.77%, edentulous patients 4.05%. H. pylori positive by EIA 318 patients' in dental plaque is found from dentate patients by EIA 9.1%, edentulous patients 14.46% and saliva from dentate patients 1.57%, edentulous patients 0.33%. H. pylori positive by culture 295 patients' in dental plaque is identified from dentate patients by culture 5.42%, edentulous patients 9.15% and saliva from dentate patients 0%, edentulous patients 0.33%. The detection rates of H. pylori in DP (6.9%) were rather low than saliva (28.6%) respectively. About half of the world population is infected with H. pylori, but the transmission and the source of this infection are still unknown.