EN
We studied pressure effects on YbCu_5 and YbInCu_4, good examples of the Yb-based compounds to investigate the nonmagnetic-magnetic transition in Yb-based strongly correlated electron systems. With increasing pressure, the low-temperature Fermi liquid state of YbCu_5 is gradually suppressed, suggesting the second-order like nonmagnetic-magnetic transition around the pressure of 5-6 GPa. On the other hand, in YbInCu_4 which has a pressure-induced magnetic ordered ground state above P_C=2.45 GPa, both high-temperature paramagnetic and low-temperature intermediate valence phases are insensitive to pressure. Our results confirm the first-order nature of the transition between the intermediate valence and magnetic ordered phases with pressure.