In the mold vulcanization molding process, the unvulcanized rubber compound is filled into the sealed mold and under high pressure and temperature, it is transformed from the unvulcanized state into vulcanized rubber. The unvulcanized rubber compound is subjected to shear forces and associated thermal history during the processing process prior to vulcanization, which greatly affects its flowability and vulcanization behavior in the mold. In order to manufacture rubber products with excellent properties and functions, the flow behavior of the unvulcanized rubber compound in the mold must be analyzed and reflected in the compound composition of the rubber compound, rubber mold design, and vulcanization conditions. For this purpose, analysis of the flowability in the mold, pressure behavior, and visualization methods have been studied, but the behavior has not yet been clarified. In addition, improvement of flowability by compounding design is also being studied.