Abstract: A research on the measuring method of the cal dielectric constant would be an important prerequisie to accurately have the coaldielectic features andwould be an important ac.ss to the dielectric physics theory and appication discoveryof the coal. According to the important role of th coaldielecric constant to thgeophyscal xploraton,the early warning of the mine geologic disasterthe coal desufuization and the research reaof the electic power and coking.based on the documentary investigation on the domesticand overseas systems the paper had a systematic analysis and sunmaization on the research progress on the domestic and overseas coal dielecric theoretical model and the measuring system and measuing method of the diletric constant.Fnaly the paper pointed out tht the present measuring methods of the cal dielectic constant were insuficient. The paper provided the proposals and comments on the late research and development tendency