A method for studying the relevance between the various phenomena during coking coal carbonization has been wistfully developed because the occurrence of the gas-liquid-solid phase makes the measurement very complicated. A thermogravimetry-plastometer-swelling pressure (TG-P-SP) apparatus was developed on a standard Sapozhnikov plastometer for simultaneously measuring not only the thickness of plastic layer but also the swelling pressure of plastic layer and its expansion effect on coal charge as well as volatile matter escaping. TG-P-SP employs an electronic balance and a Sapozhnikov plastometer, which is located on an electronic balance, with a pneumatic-loaded cylinder, linear displacement transducer, and pressure sensor. The characteristics and advantages of this method are able to give some information on the initial states of various phenomena of carbonization and pictures of complexity- and uncertainty-related behaviors in the carbonization process for coals with various rank and plasticity. These may have an important role in revealing the carbonization mechanisms and evaluating the properties and quality of coals for coke making.