Two tpyes of epoxy resin model compounds, one containing an ether bond and bisphenol-A structure (compound I) and the other comprising ether and tertiary amine bonds (compound II), were prepared and then decomposed in near-critical water (NCW). In the case of model compoundI, at low temperatures the water molecules behave as nucleophilic reagent reacting with the terminal ether group of the model compound. When the temperature is increased, the middle ether bond of the model compound molecule can be broken down. As to model compoundII, at lower temperatures, cleavage of the ether bond happens more easily than that of the tertiary amine bond because of higher positive charge density centered at the carbon atom in the ether group. At higher temperatures, the energy required to break down the ether bond is reduced dramatically after being protonated by H+, and therefore, the bond can be cleaved more readily than the tertiary amine bond. The decomposition products in both model compounds were found unstable and could react with each other to generate other compounds. Decomposition mechanisms were also proposed based on the decomposition products for the model compounds.