Study of hadronic event shapes with the CMS detector at LHC

Hadronic event shapes are studied using the first 78 nb$^{-1}$ of 7 TeV proton-proton collision data collected with the CMS detector at the Large Hadron Collider. Hadronic event shapes are used to study the geometric structure of the hadronic final state. Normalized event-shape distributions, using jet four-momenta as input, are shown to be robust against various sources of systematic uncertainty. It is demonstrated, that this early measurement of event-shape variables allows to study differences in the modelling of QCD multi-jet production.