It is known that the classical and well-outcropping Lower Permian Qixia limestone and Lower Triassic Nanlinghu limestone develop at Pingdingshan and Majiashan outcrops in Chaohu, Anhui province, between which the Pingdingshan outcrop is the first-choice one of the Lower Triassic Induan-Olenekian boundary of GSSP in China. The outcrop samples were adopted from these outcrops for analyzing biomarkers in saturated hydrocarbon. The analysis result indicates that both the dark Qixia and Nanlinghu limestones are of effective source rock with a certain hydrocarbon generation potential. The Nanlinghu limestone is characterized by high abundance of long-chain tricyclic terpane, rearranged hopane and diasterane in saturation hydrocarbon, which implies an environment of weak-prone oxidization during sedimentation. Owing to the influence of low-energy terrigenous sediments, the Qixia limestone is characteristic of terpane series in a normal distribution patter, while the sterane shows an obviously lower maturity parameter than the balance value of it. It is suggested the reason why the Qixia limestone presents high thermal evolution just is the inversion of 20S/(20S+20R)-ααα-C29 sterane and ββ/(ββ+αα)-C29 sterane values.