A set of phosphorus-containing dendrimers involving five generations (g = 1-5) has been investigated using temperature-modulated calorimetry and standard differential scanning calorimetric techniques. The dendrimers show a complex glass transition temperature with a generation dependence. Enthalpy relaxations have been pointed out in this complex architecture macromolecule. Physical aging manifestations are studied vs complexity growth, with various cooling. The thermal manifestation intensity of physical aging decreases with generation.