Banyumas Basin is a basin that has signs of the presence of hydrocarbons, including oil and gas seep on the surface, which indicates active petroleum systems in the subsurface. A lot of oil and gas seeps were found in Banyumas Basin, including oil seeps in Cipari and Besuki, while gas seeps were found in Mount Wetan, Karanglewas, and also Cipari. Exploration drilling wells have also been carried out, such as the Jati-1 Well, Karang Nangka-1, Karang Gedang-1, Tjipari-1, and Mount Wetan-1, but there still has been no significant evidence of this basin producing hydrocarbons. The TOC value of the outcrop samples taken in Cipari and Besuki have bad values, while the crude oil has reflected a severe biodegradation process. Both oil seep samples and one extract bitumen contained high bicadinane (R (resin) annotation) and oleanane indicating both oils and extract to have an input to Tertiary-sourced oils throughout Southeast Asia. Both oil seep samples do not exhibit similarity with the extract source rock. Based on this negative correlation there may be another source rocks in Banyumas Basin, derived from rocks that are not only from Pemali Formation. The existence of this research is expected to be able to add geological data, especially hydrocarbon geochemical data in Banyumas Basin, so that it can provide evidence of the prospect and calculation of reserves contained in this basin, and an understanding of the source rock it self.