2D and 3D thermal history and organic matter maturity modeling of East Siberian Sea sedimentary basinsare performed in this study. We present cross-sections with temperature and vitrinite reflectance distribution along composite seismic line, temperature maps ofmain horizons fordifferent time stages. Vitrinite reflectance maps of source rocks fordifferent time stages and transformation ratio maps of source rocks for present time are also presented. Maturation history and possibilities of hydrocarbon generation were analyzed using modeling results.