QCD at LHC with ATLAS

The LHC will allow QCD studies to be performed at very high energy, including precision tests and measurements in an as yet unexplored kinematic region. A detailed understanding of QCD is important for almost all physics processes to be studied at the LHC, as the production mechanisms are mostly controlled by QCD. This talk will review various measurements of QCD-related processes to be performed at the LHC, based on final states containing leptons, photons and jets. The kinematic reach and the expected statistical uncertainties will be described for selected examples. The achievable constraints on the parton distribution functions of the proton and a measurement of the strong coupling constant at very large scales will be presented. Where already studied, sources of systematic uncertainties and contributions from background processes are going to be discussed.