Abstract: Colloidal gold immune chromatography technology was applied in this study, the colloidal gold immunochromatographic test strip was developed in order to establish a rapid detection assay of benzoic acid. The colloidal gold with particle diameter 17nm was obtained by reducing gold chloride with sodium citrate, benzoic acid gold-labeled antibody was spotted on some chosen glass fiber made of colloidal gold combined pad, and the antigen of benzoic acid and Goat anti Rabbit IgG were coated on the nitrocellulose membrane to be the test line (T line) and the control line (C line) . Test strips were constructed and the detection sensitivity was measured. Results showed that the detection limit of colloidal goldimmunochromatographic test strip was 100μg/L and the whole analysis process could be completed within 5 ⁷min. With phenol, toluene, benzene acetic acid, phenylalanine and other drugs had no cross reaction:Results were in complete accord with enzyme-linked immunosorbent method. The method had simple operation, fast characteristics, strong specificity, high sensitivity. The colloidal gold immunochromatographic test strip could be widely used for On -site rapid detection and screening work and had great prospectfor commercial development.