The dynamic mechanical properties of Eucommia ulmoides (EU) gum with different degree of cross-linking are studied systematically in this article. EU gum displays five dynamic mechanical behaviors with increasing degree of cross-linking. Before elastic critical turning point, EU gum shows two active dynamic mechanical temperature zones with rising of temperature, one is T (g) zone, controlled by glass transition mechanism, the other is T (m) zone, controlled by crystalline melting mechanism, its tan delta values at T (g) zone and T (m) zone during the process of cross-linking obey the dynamic reverse transition law: at the T (g) zone, the peak value of its tan delta is proportional to cross-linking degree inversely proportional to crystallinity degree; at T (m) zone, its tan delta value is proportional to crystallinity degree and inversely proportional to cross-linking degree. In addition, the T (g), T (m), and X (c) of the EU gum with different degrees of cross-linking are obtained as well.