Provided are phase change random access memory (PRAM) devices and methods of operating the same. The PRAM device may include a switching device, a lower electrode, a lower electrode contact layer, a phase change layer and/or an upper electrode. The lower electrode may be connected to a switching device. The lower electrode contact layer may be formed on the lower electrode. The phase change layer, which may include a bottom surface that contacts an upper surface of the lower electrode contact layer, may be formed on the lower electrode contact layer. The upper electrode may be formed on the phase change layer. The lower electrode contact layer may be formed of a material layer having an absolute value of a Seebeck coefficient higher than TiAlN. The Seebeck coefficient of the lower electrode contact layer may be negative. The material layer may have lower heat conductivity and/or approximately equivalent electrical resistance as TiAlN.