Network structure of a stoichiometric mixture of diamine cured epoxy (DGEBA/DDS) was investigated by fluorescence and IR spectroscopy techniques. The structure of epoxy network was varied via processing condition to produce a series of samples with different extent of epoxide cure. Fluorescence spectra provide the extent of amine epoxide addition reaction, and IR spectra give the overall extent of epoxide reaction. Comparing both spectra indicates that the extent of amine epoxide addition reaction is fairly close to the extent of epoxide reaction increases further even after the amine epoxide addition reaction reaches its saturation point. DSC results also confirm ether formation at later stage of cure. Tensile properties and fracture toughness of these samples were investigated in terms of network structures from two different types of cure reaction. An epoxy with higher amount of ether linkage resulted in lower tensile modulus, higher tensile strength, and lower fracture toughness. Such changes in properties could be explained in terms of nodular morphology.