Physics beyond the standard model and collider phenomenology

We review the Standard Model of the particle physics in details focussing on the gauge hierarchy problem and the naturalness problem regarding the stabilization of the light Higgs mass. We list the alternative modals which address the hierachy problem in addition to conventional Supersymmetric models and Composite models. They include extra dimensional models and Little Higgs models. The collider phenomenology of the TeV-scale string scenario has been studied. Some low-energy aspects of the stringy amplitudes have been discussed in both coincident-branes and intersecting-branes models. The current lower bound on the string scale is 1.2--2.1 TeV from the Tevatron and the reach at the LHC at 300 fb-1 luminosity is 8--10 TeV.