The Large Hadron Collider (LHC) at CERN will provide proton-proton collisions at a centre-of-mass energy of 14 TeV and a bunch crossing interval of 25 ns. At design luminosity, L = 10³⁴ cm^-2 s^-1\mathcal{L} = 10^{34} {\rm cm}^{-2} {\rm s}^{-1} , an average of 17 collisions will occur at each bunch crossing, resulting in a billion inelastic pp interactions per second. The CMS (Compact Muon Solenoid) experiment is designed to study these high energy proton-proton collisions to understand electroweak symmetry breaking and to search for new physics processes. In the search for new physics identification and precise reconstruction of electrons, photons and muons will be a key issue. This article describes the layout and the simulated performance of the E photon and muon reconstruction algorithms, designed in the framework of the High Level Trigger software, are described.