Cross-linking reaction kinetics of ethylene-vinyl acetate (EVA) copolymer initiated with dicumyl peroxide is studied by differential scanning calorimetry (DSC) and a cross-linking rheometer. As the degree of cross-linking (alpha) is less than 0.30, EVA can flow relatively freely because of insufficient cross-linking. As alpha ranges from 0.31 to 1, there is more of the cross-linking reaction, and the polymer becomes fully cross-linked in the later stage of the reaction so that three-dimensional crosslinked nets have been constructed. New kinetics approaches are proposed on the basis of the cross-linking parameters measured with the cross-linking rheometer incorporated into Hill and Avrami mathematical equations. As the cross-linking rheometer is popular in manufacturing the cross-linked EVA, the approaches are simpler and more convenient than the DSC method for fast studying kinetics of the cross-linking reaction of polymer in solid or melting state. The total cross-linking reaction rate changes with alpha, and the apparent activation energy is 91.2-175.0 kJ/mol.