The goal of the present paper was to find effective biochemical markers of chronic narcotization. Materials and methods. The results of biochemical research of biological liquids in human organism and chromatographic methods of drug substances identification in cadaveric urine were analyzed. Research of 197 samples of different biologic liquids of 10 persons was carried out. Control was fulfilled on the basis of 135 samples of biological liquids took of 12 persons. Methods of identification of drug substances are presented, chromatographic and spectral characteristics of drug substances are described. Interrelations of biochemical indices at positive study of drug substances identification were conducted. The increased urea metabolic concentration in cadaveric blood of drug addicts was revealed in comparison with control specimens. Results. (Numeral results are given in Table 3). Correct correlation of biochemical markers was not established. Conclusion. The present results suppose continued study of informative reliable biochemical markers of chronic drug intoxication