An analytical strip and a detecting method using the analytical strip are provided. The analytical strip includes a substrate having a channel thereon. The channel has a first region, a second region and a third region, which are arranged successively. A first antibody is localized in the first region. A saccharide and a peroxidase are localized in the first or second region. A second antibody for recognizing a different epitope of an identical antigen with the first antibody is immobilized in the second region. A substrate reagent including a saccharide oxidase is localized in the third region.