A third-generation cephalosporin antibiotic was aceftriaxone medicine. Similar another (3rd generation cephalosporins), it has wide broad spectrum effectiveness versus gram positive as well as gram negative bacteria. Diverse approachs for analyses of the studied medicine are obtainable but are costly additionally time consumption. Therefor we have sophisticated developed novel, easy, simple as well as accurate colormetric approach for investigation of ceftriaxone medicine as pure form as well as in formulation vials by depending on  a specific color-generated reaction. This reaction involves the Schiff 's base formation reaction between ceftriaxone drug  with alcoholic 4- di ethyl amino benzaldehyde  (DEAB) reagent to produce a new ligand that reacts with cobalt (II) ion with heating to (50°C) in acidic media to form green colored complex exhibiting λmax at 496 nm. The medicine conformed with the Beer’s law with the linearity was observed between (2 –52) μg/ml additionally that  correlation coefficient was 0.9992 .The analyses outcomes were supported with LOD, LOQ, accuracy, recovery studies, ruggedness as well as precision. The approach was establish to be robust as well as economical.