This paper reports the results of numerical estimation of the degree of organic matter maturity and hydrocarbon generation in the rocks of the Bremer 1–6 formations during the burial of the sedimentary basin of the Mawson Sea on the passive margin of East Antarctica. Numerical simulation of basins was conduced for 15 areas along two profiles, 5903 and 5909, in the eastern and western parts of the Mawson Sea. The calculations revealed correlations between the yield of various hydrocarbon fractions and vitrinite reflectance in the supposed source rocks of the basin. Using these correlations, the generation characteristics of the rocks of the Bremer formations in the eastern and western Mawson Sea were compared. It was shown that the rocks of the Bremer 1–4 formations are mainly gas-prone in the eastern part of the basin, but could generate heavy and light oil in the western part of the basin. On the other hand, it was suggested on the basis of modeling that the rocks of the least buried Bremer formations (Bremer 5 and 6) produce mainly heavy oil in the western part of the Mawson Sea and light oil in its eastern part.