For Publisher’s use QCD REVIEW

In 1973, with the discovery of asymptotic freedom , QCD was at the frontier of particle physics studies. Now, in 2006, QCD is strongly installed (returning) at the center of particle physics researches. This, not only because of the abundance of data on jet emission at HERA and Tevatron, but especially for the necessity of preparing tools for discoveries at LHC. Indeed, events with large ET , as in the decay of new massive particles, are accompanied by intense hadron emission. So the interpretation of a new elementary process requires an accurate description of short distance hadron physics, and this is the domain of perturbrative QCD. Therefore calculations have been performed in recent years in order to produce accurate hard physics predictions for LHC. The results of high order QCD studies go beyond their phenomenological importance, they are exposing various new features of Feynman graphs which may point to new general properties of quantum gauge theories. Moreover the possibility that QCD can be viewed as a solvable string theory is getting strength after the discovery of the AdS/CFT correspondence. In the last two or three years this fact encouraged studies of “solvable” string theories leading to phenomenolgical results in QCD. QCD studies are developing in many directions and I can discuss only a limited number of points. Before describing NLO results with their relevance for phenomenology and for understanding new features of QCD in general, I describe new avenues of the phenomenological attempts to connect QCD with string theory and its impressive list of results.