Based on a study of the electromagnetic characteristics of marine carbonate samples collected in southern China, the authors have reached the conclusion that shale beds typically show low resistivity on sections in marine carbonate areas, and this means that the shale beds can be identified with electromagnetic technique. In addition, measurement data of rock samples and core samples show that organic-rich shale beds have high polarization, which is closely related to high TOC, and this implies that we can identify‘sweet spot’ area of shale gas by using polarization anomaly. TFEM (Time and Frequency Electromagnetic) combines both time-domain sounding and frequency-domain sounding into a joint system, which induces target shale beds with a high-power transmitter. The method can help seismic technique to quickly identify target‘sweet spot’ of shale beds. The authors firstly analyze the physical properties of target shale beds, and then demonstrate the method for extracting electric and polarization anomalies aiming at the target beds. The combination of TFEM and seismic method makes the shale beds exploration more economical. This paper introduces this new and effective approach for quick identification of‘sweet spot’ and improving the success rate of shale gas exploration.