Based on relativistic Born approximation theory, we have calculated the relati-vistic and non-relativistic generalized oscillator strengthes (GOS) of the Li-liks iso-electron sequence. The difference between the two calculations shows the relativistic effect of both the target and impact electron in the inelastic collision process. For low Z target (e.g. Li), the relativistic effect is negligible. For the 2s?p transition of Au+76, the relativistic GOS is 27.1% smaller than the non-relativistic one. At high impact energy, the contribution of transverse term of GOS to the differential cross section is important at certain angle. At extremely high impact energy (e.g. 106, 107eV), the transverse term of GOS becomes dominant at forward small angle and such forward peak makes overwhelming contribution to the totalinelastic cross section.