Abstract: The purpose of this study is to evaluate a rapid microdose 14C -urea breath test (14C-UBT) with a simplified protocol for detecting the infection of hilicobacter pylori (HP). 244 fasting patients with upper gastrointestinal symptoms undergo the 14C-UBT and 124 cases appear positive. 89 patients of those undergo upper gastrointestinal endoscopy and confirmed as HP infection. The sensitivity and specificity of the 14C-UBT is 100% when compared with the endoscopy. The test has good diagnostic accuracy with minimal radiation exposure and low cost. Thus, the test is reliable, safe, convenient and cost-effective to clinical use.