The quantity and thermal maturity of organic matter in the present study are discussed throughout the Rock-Eval pyrolysis for 27 rock samples of Tut -1x well used to describe the quantity, type, maturity, and petroleum generative potentials of prospective source rock horizons. The results showed that Alam El Bueib Formation has type-III kerogen. Masajid, Khatatba, and Ras Qattara Formations display mixed kerogen type II-III, which has the ability to generate mixed oil and gas accumulations under thermal maturation. Meanwhile, Alam El Bueib and Masajid Formations entered the early mature stage of oil generation at vitrinite reflectance values of 0.60 Ro%. The source rock of the Khatatba and Ras Qattara Formations reached to the peak of oil generation at vitrinite reflectance values of 1.36 Ro%. This indicates that Khatatba and Ras Qattara Formations can be consider to have generative potentials of prospective source rock horizons in the Tut-1x well.