Abstract: Colloidal gold immunochromatography assay concentration detecting method uses the colorimetric principle, which compares with the color standard card by using color varietal detection area, after a reaction between antigen of the measured liquid and antibody of the reagent strip. It-s a qualitative concentration analysis. At present, colloidal gold test strip is mostly semi-quantitative, which tends to limit its use. It adopted an embedded image processing system which based on the digital signal processor (DSP). The image information of the quantitative colloidal gold test strip was sampled by the image sensor complementary metal oxide semiconductor (CMOS), dealt by Bayer transformation, white balance processing, image feature information of fringe intensity extraction, and then established the functional relation between image feature information of fringe intensity and sample concentration, so it can realize accurate measurement. Compared with other methods, it has advantages of high precision, fast inspection speed and so on. The results show that the method of quantitative colloidal gold test strip concentration detection has upper applied value,which based on the DSP hardware platform, it precision can be up to ±5%,repeatability error reaches ±1%.