The elastic modulus versus crystallinity linear relationship in Polyethylene (PE) is re-examined via meticulous measurements over a wide set of PE. First, large discrepancies to linearity are observed; moreover, Raman spectroscopy revealed that the content of the so-called interphase exhibits considerable variations over the set of PE. Therefore a novel strategy based on DMA is developed for a better identification of the modulus of each phase along the temperature. On the one hand, below the alpha and beta relaxations, the young modulus proved to be linearly dependant on the sum of the crystal and interphase content. On the other hand, between the alpha and beta relaxations, the interphase appears surprisingly as stiff as the crystal. In addition, the quenched samples exhibit a particular behavior. A simple model has lead to the conclusion that their mechanical coupling and/or amorphous modulus are significantly different as compared with all others materials. (C) 2011 Elsevier Ltd. All rights reserved.