It is attempted to study the nucleon-nucleon interaction in the several GeV energy region by analyzing elastic proton-proton scatterings at 6 and 12 GeV/c in the impact parameter representation with all the five spin-dependent eikonals. It is shown that one-pion-exchange and one-boson-exchange-like mechanisms still work in this energy region and, in addition, short-range forces of range 0.2∼0.5 fm and of magnitude 100∼200 MeV exist in the innermost region. The ``soft core'' remains and its strength reduces when the energy goes up from 6 to 12 GeV/c. Along with these vestiges of low-energy nuclear forces, the eikonals and the scattering amplitudes show a definite energy-dependence like the Regge-pole exchange and various high-energy features. The energy-dependences between 6 and 12 GeV/c are discussed in detail.