Proton knockout reactions on carbon isotopes, p(C9-16,2p)8-B-15, at 250MeV/A were performed for systematic information on weakly to strongly bound 1p valence protons and deeply bound 1s protons. Various information such as energy gap between is and 1p orbits, widths of momentum distributions for 1s and 1p orbits, relative(p,2p) yields are obtained.