 In this paper, the influences of the graphite precursor and the oxidation method on the resulting reduced graphene oxide, especially its composition and morphology, are shown. Three types of graphite were used to prepare samples for analysis, and each of the precursors was oxidized by two different methods, all samples were reduced by the same method of thermal reduction. Each obtained graphite oxide and reduced graphene oxide was analyzed by X-ray diffraction, XRD, X-ray photoelectron spectroscopy, XPS, and Raman spectroscopy, RS. This article was authored by Roxana Musica, Sabina Drunyak, Tadeash Pustulny, and others.