This thesis describes a precise measurement of the muon charge asymmetry in √ inclusive pp [RIGHTWARDS ARROW] W + X production at the center of mass energy of s = 7 TeV of colliding protons. The data sample was collected with the Compact Muon Solenoid detector at the Large Hadron Collider and corresponds to an integrated luminosity of 4.7 fb[-]1 . The measurement was performed in 11 bins of the muon pseudorapidity within |[eta]| < 2.4 range and for two thresholds on its transverse momentum: pT > 25 GeV and pT > 35 GeV. Precise measurement of the muon charge asymmetry provides an important test for the Standard Model physics. Thanks to the large data sample, containing more than 20 million W [RIGHTWARDS ARROW] [MICRO SIGN][nu] events, statistical precision is greatly improved compared with the previous lepton charge asymmetry results at the LHC. Total absolute uncertainty on the charge asymmetry varies within 0.2% [-] 0.4% in different muon pseudorapidity bins. The result provides significant constraints on the parton distribution functions of the proton in the Bjorken-x range from 0.001 to 0.1.