Interest in graphite fillers has grown since the separation of graphene from graphite by micromechanical cleavage [1]. More especially, one of the interests is to understand the influence of graphite microplatelets, with different size, on the crystallization behavior of a polymer matrix, after elaboration by melt mixing. The selected matrix is a neat polypropylene (PP), referenced as Moplen HP400R (LyondellBasell). The selected expanded graphite particles are KNG-180, KNG-150 [2] and KNG-G5 [3] (Knano®). Composites with three volume fractions of graphite varying from 0.3 to 2 % are concerned. The dispersion state of the particles in the composites is characterized at different scales using SEM and TEM; and crystallization using optical microscopy, DSC and X-ray diffraction. The discussions deal with the strong kinetics enhance of crystallization, at a given volume fraction, in the presence of respectively KNG-150, KNG-G5 and KNG-180. The expanded graphite particles are found to have a flake shape with a micrometric size. KNGs act as nucleating agent and induce an epitaxial growth of alpha crystalline phase of PP, but related to the difference in stacking dimension of graphite particles [4]. Radial growths are also observed, randomly located as classically reported. The coarsest and ordered KNG favors PP transcrystallinity, in such a way that (040) plane of PP is parallel to (002) plane of graphite platelets. Acknowledgement Expanded graphite particles were kindly provided by the CNRS research group project n°3661 ‘GDR PolyNano’. [1] K.S. Novoselov, Science 306 (2004) 666 [2] G. Chen, C. Wu, W. Weng, D. Wu, W. Yan, Polymer 44 (2003) 1781 [3] W. Zhao, F. Wu, H. Wu, G. Chen, J. Nanomater. (2010) 528235 [4] P. Sowiński, E. Piorkowska, S.A.E. Boyer, J.-M. Haudin, K. Zapala, Colloid Polym. Sci. 293 (2015) 665