The Large Hadron Collider (LHC) is the world's largest particle accelerator where beams of protons will be brought to collision at an unprecedented center-of-mass-energy. Almost all physics channels of interest at the LHC require a good understanding of Jet clustering and and the Missing Transverse Energy (MET) reconstruction. I will report on the current simulation studies regarding the reconstruction of Jets and MET with the CMS detector at the LHC. The performance of various jet algorithms as well as the performance when using the measurements from the Calorimeter and the Tracker as an input to these algorithms will be discussed. The plan for obtaining the Jet energy calibrations will be outlined and the data-driven correction methods will be discussed. Finally, the performance of MET reconstruction will summarized with an emphasis on its importance on the discoveries beyond the Standard Model.