Drug addiction is one of the biggest problems of medicine because diagnosis and treatment of drug addiction are difficult compared with some other socially significant diseases. In this study, synthesis and evaluation of four carrier protein-morphine conjugates were experimented. These conjugates were evaluated based on ELISA; soybean protein-based conjugate was selected for further analysis. The total soybean protein was isolated from the local soybean variety and; it was fractioned by the gel-filtration method and their amino acids compositions were studied. After that, the ELISA drug addicts were conducted based on soybean protein-morphine conjugates synthesized with soybean protein fractions. The high molecular weight soybean protein- morphine conjugate showed the highest quality.