Abstract: Based on the solidificaton process of carbon stcel in continuous casting mold, and considerin the colltact behavior between billet and mold, a fully thermomechancally coupled 2D transient thermo-elastoplastic FEM model is established. The model is thelemented with MAR software on PC computer, and the thermal and mechanical states in continuous casting mold are obtained, especially including the interfcial states between shell and mold, such as billet surface temperature,interfacial heat flux and the law of gap formation. This analytcal work can provide theoretical bases for optimizing mold taper and developing high-speed casting mold with coninuously changing taper.