Title: Partonic showers and jets Author: Ondřej Hladík Department: Institute of Theoretical Physics MFF UK Supervisor: Mgr. Alexander Kupčo, Ph.D., Institute of Physics ASCR, v. v. i. Abstract: In the present thesis we compare experimentally measured differential and integrated jets shapes with predictions of quantum chromodynamics (QCD) at the second order (NLO) of perturbative expansion. The measured jet sha- pes were taken from ATLAS experiment at LHC in proton-proton collisions at a center-of-mass energy √ s = 7 TeV and were compared with these predictions. The jets were reconstructed by means of anti-kT jet algorithm with R = 0.6. The predictions at NLO QCD agree with data in wider kinematics region than predictions at leading order (LO). The agreement, however, is still in some kine- matical regions not satisfactory. Keywords: QCD, jets, jet shapes, LHC