PDFs Determination from the LHeC

Deep Inelastic Scattering would be brought into the unexplored TeV regime by the the proposed Large Hadron Electron Collider at CERN. Its rich physics program, includes both precision Standard Model measurements to complement LHC physics as well as studies of QCD in the high energy limit. The present proceeding reports on studies included in the updated LHeC Conceptual Design Report. We study the impact of LHeC simulated data on Parton Distribution Functions uncertainties. We also assess the LHeC potential to allow the determination of the strong coupling constant α_S, at per-mille level as well as to disentangle between various scenarios of small-x QCD.