The hydrocarbon source rocks of the Weibei Sag, Changwei Depression, Shandong, are distributed in the Second Member of Kongdian Formation, Eocene, include dark mudstone, calcareous mudstone and oil shale. There have been a few studies on hydrocarbon generation of calcareous mudstone and oil shale before. The aim of this paper is to review the characteristic and distribution of different types of hydrocarbon source rocks.The study is conducted at organic geoehemistry combined thermal simulation experiment, and the result shows that high abundance of organic matter in oil shale and calcareous mudstone, which kerogen are mainly typeⅠand typeⅡ1, are high quality hydrocarbon source rocks. Dark mudstone generally are invalid hydrocarbon source rocks. The high quality hydrocarbon source rocks longitudinally concentrated on the upper and middle of the Second Member of Kongdian Formation, laterally distributed in Zaohu and eastern part of the Wacheng fault zone. Ancient sedimentary environment is analyzed by paleontological marks, paleosalinity and paleoxygenation facies, reveals that high quality hydrocarbon source rocks of the Second Member of Kongdian Formation formed in the inland saline lakes environment. The cause of high quality hydrocarbon source rocks are the weak intensity of tectonic activity of Tanlu(Tancheng—Lujiang) fault zone during the conversion period from left slip to right slip and the warm and humid climate aroused by the mainland separation incidents occurred in the Late paleocene to Early Eocene.