Diffusion-influenced reversible reactions of polymers are investigated by using the hierarchical reaction-diffusion equations for end-functionalized Rouse chains. It is found that distinct dynamic characteristics of reactive groups over different time scales lead to rich time-dependent behaviors in the reactant number densities, which are totally absent in the small molecular reactions. On time scales smaller than the Rouse relaxation time, the number densities of excited reactants are described by a scaling function, whereas for larger times, they approach the equilibrium values exponentially. A kinetic phase diagram locating regions of distinct behaviors of Stern-Volmer coefficients is presented which can be directly confirmed by experiments.