© 2016, Editorial Office of ACTA PETROLEI SINICA. All right reserved.Based on drilling, logging and seismic data, as well as seismic profile interpretation, seismic attribute analysis and other means, this study performs a systematical identification of the Cenozoic diabase rock in Fangzheng faulted sag, NE China, and also discusses its hydrocarbon geological significance. Cenozoic diabase rock stocks, sills and other intrusive mass are widely developed in the northeastern Fangzheng faulted sag, characterized by low values of natural gamma and acoustic transit time as well as high value of electrical resistivity in logging. Chaotic reflection occurs on the seismic profile, whereas the boundaries of rock are often featured by strong reflection and high amplitude anomaly. These intrusive mass has irregular spatial shape, but overall extending in a NE direction, and approximately parallel to the sync-activating NE-trending major faults, which is formed under extensional or transtensional tectonic setting. This might be related to the Mid-Oligocene (about 30 Ma) and Mid-Miocene (about 13 Ma) basic-magma thermal events. The vitrinite reflectance (Ro) data of mudstone show that the thermal evolution in the northeastern faulted sag had a significant high-value anomaly. In combination with the analysis of structural evolution, it is suggested that the intrusion of Cenozoic diabase significantly elevated the local geothermal field, which leads to the fact that the maturing of source rocks is accelerated by abnormal thermal evolution In addition, the diabase intrusion can result in multiple related hydrocarbon traps, which may be potential hydrocarbon exploration targets in Cenozoic basins of NE China in the near future.