QCD Results from ATLAS

ATLAS results of measurements of both soft- and hard-QCD are presented the first data produced by the LHC. Distributions of jets reconstructed using either calorimeter or Inner Detector information are compared to the Monte Carlo simulation. The calorimeter response to isolated hadrons is shown to be described by the simulation to within 5%. The first measurements with the ATLAS detector at the LHC on the properties of proton-proton interactions are presented. The charged-particle density, its dependence on transverse momentum and pseudorapidity, and the relationship between transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range $|eta|< 2.5$ and $p_T > 500$~MeV at $sqrt{s} = 900$~GeV and $sqrt{s} = 7$~TeV. The measurements are compared to minimum bias Monte Carlo model predictions. This was first presentation by ATLAS of charged particle multiplicities at 7 TeV.