Multivalent structure with carbohydrate moieties and its biological properties have been studied. Novel method for synthesizing gold-nano-particles carrying carbohydrate moieties have been developed and the method is much more convenient than a traditional method. Expection of the glyco-gold-nanoparticle is display of multivalent carbohydrate moieties on the surface and show of effective interaction with pathogens. In addition it has capability of applying to diagnostric use such as medical test kit.