Chemical energy plays a big role in the process of modern Electric Arc Furnace (EAF). The objective of this study is to compare the results of chemical reaction enthalpies calculated by four different methods. In general, the “PERRY-NIST-JANAF method” is used to calculate the chemical energies. However, this method heavily depend on heat capacities of the substances which have to be deduced from  “Perry’s Chemical Engineers’ Handbook” and “NIST-JANAF Thermochemical Tables”, even the calculation process is complicated. Then, some other methods are introduced: Total enthalpy method, HT (High Temperature) enthalpy method and Atomic energy method. In this thesis, the above four methods have been used to calculate the enthalpies of chemical reactions in EAF process. Both of “Total enthalpy method” and “HT enthalpy method” are not complicated, but some basic data are not available. The calculation for chemical reaction enthalpies cannot be completely made by these two methods. “Atomic energy method” is more complicated than “Total enthalpy method” and “HT enthalpy method”, even almost all data are available, but some results of these methods are far from those of the other three methods’. The results show that values of enthalpies obtained by “PERRY-NIST-JANAF method” are more reasonable, though the calculation process is more complicated. In this study, it is also discussed two influencing factors on EAF process: electric power and electromagnetic stirring (EMS).