Immunological rapid urease test for detection of Helicobacter pylori infection, composed of a solid-phase tip coated with monoclonal antibody against H. pylori's urease and ion-sensitive field transistor (ISFT)-based pH sensor system, was developed. The monoclonal antibody against H. pylori's urease was useful to avoid the contamination of urease activity in other bacteria. Because ISFTT had high ability to detect pH change, the sensitivity and specificity of immunological rapid urease test was significantly improved comparing with that of conventional rapid urease test. The utility of immunological rapid urease test was evaluated in some clinical studies.