In the article the first experience of the system description of tool traces on the surface of the old Russian parchment is undertaken. The research is based on the study of codes of late XIV – early XV centuries from the collection or Russian National library. Methodological basis of research is theoretical and methodological apparatus established in the framework of forensic trace analysis. Trasological research of manuscripts was carried out with the help of a specialized hardware complex designed for their expert study. Traces were detected by examining objects in oblique light, simultaneously fixing observed in the visible region of the spectrum and visualization and registration in the near infrared (IR) range. The study identified three main groups of traces: 1) traces of special knives, which depending on the intensity of action may look like a wide scratch, incision, or hole; 2) traces having the form of regularly (after an equal interval) alternating convex and concave grooves, which should be associated with the use of a scraper with a curved edge; 3) traces of grinding, apparently, pumice, which may have the form of planar scratches, or shallow grooves.