The topic of the thesis is the enhancement of the oxidation resistance of carbon in refractories. First a literature research has been carried out, to find out different options to improve the oxidation resistance of carbon. The second part of the thesis was to test some selected methods on carbons, which are important for the refractory industry. They were tested on the binders pitch and resin and on graphite, micro-graphite and carbon black. The materials were treated with organic chlorous compounds and inorganic acids, salts and anhydrides. After preparation, which included coking of some specimens, all specimens were investigated by a thermogravimetric analysis in synthetic air. The beginning of the oxidation and the remaining mass were determined from the diagrams received. To check the effectiveness of the chemical treatments these data were compared with the data of the original specimens. One substance was identified, which was able to increase the temperature of oxidation beginning and decrease the mass lost.