The mixture of psychotropic drugs aminazine, barbamylum and nitrazepam using ultraviolet (UV) spectrophotometric method was researched. As the solvent, most acceptable for identification and differentiation of these preparation was found 0.1N solution of sulphuric acid. By measuring the optical density of the solutions in different concentration the calibration diagrams for all preparations were made. The standard deviation, by determining the quantity of aminazine is 2.8; 4.0; 4.3; barbamylum--1.0; 2.5; 1.15; nitrazepam--2.64; 1.0; 1.35.