The author analyzes theoretical and applied aspects of diagnosing personality traits on the example of appraising drawings of a tree (according to K.Koch) made by subjects with character accentuations. The author suggests an interpretation of the structure of graphic material proceeding from the hypothesis that a drawing is a reflection of a whole creative act on the levels of the conscious and the subconscious. The paper also contains an experimental appraisal of character traits on the basis of the graphical content of drawings.