Physical miscibility at ambient and chemical interactions at elevated temperatures between a difunctional epoxy of diglycidylether of bisphenol-A (DGEBA) and a linear phenylhydroxyl-containing polymer, poly(4-vinyl phenol) (PVPh), were investigated by differential scanning calorimetry, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy, and solid-state C-13 nuclear magnetic resonance (NMR). The DGEBA/PVPh mixture was proven to be homogeneous and miscible. At elevated temperatures, the epoxy/PVPh mixture developed a network-like homogeneous solid, which was a result of reactions between the epoxide of DGEBA epoxy and phenylhydroxyl of the linear PVPh polymer. By using FT-IR and solid-state C-13 NMR techniques, mechanisms of reactions leading to a homogeneous network between the DGEBA epoxy resin and PVPh polymer have been probed.