Metamorphic rocks with graphite contents from 0.1 wt. % to 4 wt. % were analysed using Oxyreactive Thermal Analysis as a main tool with supporting X-ray and optical methods. Two generations of graphite were found in these rocks: 1. predominant graphite Gph₁ of organic origin (graphitized petroleum coke); 2. hydrothermal graphite Gph₂, in association with postmagmatic muscovite, albite and quartz. The P-T conditions of final graphitization for Gph₁ were assumed as 7.5–10 kbar and 700–780 °C. The hydrothermal graphite precipitation took place at the temperature of 700–730 °C and pressure about 6 kbar and continued during cooling up to 400 °C and 2 kbar of pressure.