Magnetic properties are investigated for top- and bottom-type spin valves of Si/SiO/NiO(60nm)/Co(2.5nm)/Cu(1.95nm)/Co(4.5nm)/NOL(t nm; Nano Oxide layer). The MR ratios of the bottom-type spin valves with NOL are larger than those of the top-type spin valves. However, the enhancement of the former is lower than the latter. Both of spin-valves also showed almost constant Ap and smaller p. Enhanced MR ratios of spin valves with NOL result mainly from small values of with constant Ap which due to specular diffusive electron scattering at NOL(NiO)/metal interfaces.