The dielectric relaxation behavior of miscible poly(4-vinylphenol)/poly(ethyl methacrylate) (PVPh/PENTTA) blends has been studied using broad-band dielectric spectroscopy in the frequency domain from 10(-2) to 10(7) Hz and at temperatures between 30 and 180 degreesC. The alpha and beta processes are resolved from the dielectric spectra by modeling with Havriliak-Negami (HN) functions. PVPh enhances the splitting between the alpha and beta processes and provides a better understanding of the splitting and merging mechanism. Arrhenius plots support the proposal that the alpha and beta processes have the same molecular origin above the merging temperature. The local beta process in the blends originates from side-chain rotation of PEMA and is only slightly influenced by PVPh. On the other hand, the alpha process includes contributions from both components, and its relaxation time increases rapidly with PVPh concentration. However, a fragility plot reveals that the presence of PVPh does not change the cooperativity beyond shifting T-g for the blends, which is inconsistent with the energy landscape model. The relaxation time for the merged a process also increases significantly as a result of the participation of PVPh. Because of the strong hydrogen bonding between PEMA and PVPh, the blends exhibit only slight dielectric broadening or concentration fluctuations.