Résumé : The nuclear modification factors of J / ψ and ψ(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of sNN=5.02TeV. The analysis is based on PbPb and p p data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464μb-1 and 28pb-1, respectively. The measurements are performed in the dimuon rapidity range of