The chromatic detecting system for neomycin was fabricated using the diacetylene compound. Three kinds of the diacetylene compounds were used in this study. Among these compounds, only the compound which has an amino group showed the chromatic activity for the aminoglycoside antibiotics. Because this system did not get the response to glucose and glucosamine which get the similar molecular structure with aminoglycoside antibiotics, I can say that both more than 3 glucose units and amino functional group were needed to show the chromatic activity. The order of the detecting ability to the aminoglycoside antibiotics was neomycin > gentamycin ≫ streptomycin in which this order agrees with the order of increasing the number of the amine functional group. The fabrication of the chromatic detecting system for neomycin was accomplished without the difficult synthesis of complicated detecting unit.