Abstract: The research aims to develop colloidal gold immunochromatographic test strip for rapid detection of E. tarda. The purified polyclonal antibody was labeled with the colloidal gold which was synthesized by trisodium citrate disoxidation method. Goat anti-rabbit IgG and purified polyclonal antibody were separately sprayed on the nitrocellulose membrane as the controlline (C line) and the test line (T line) to detect E. tarda in the samples. The results indicated that E. tarda gold immunochroamatography diagnostic strips established in this study displayed perfect specificity without cross-reactions with E. coli, S. aureus, V. anguillarum, V. harveyi, A. hydrophilia and E. ictaluri. Besides the high specificity, its sensitivity reached 105 CFU/mL and the reaction time only need 5 to 10 minutes. The dipstick was also used for detection of E. tarda in infected turbot ascites fluid. The results revealed that the test strip has good sensitivity, specificity and stability, which is easy to operate and can be used for rapid diagnosis of E. tarda.