Résumé : The production cross section of a W boson in association with two b jets is measured using a sample of proton–proton collisions at s 8TeV collected by the CMS experiment at the CERN LHC. The data sample corresponds to an integrated luminosity of 19.8fb-1. The W bosons are reconstructed via their leptonic decays, W → ℓν, where ℓ μ or e. The fiducial region studied contains exactly one lepton with transverse momentum pTℓ>30GeV and pseudorapidity