We present results of Raman spectroscopy and magnetic susceptibility measurements in the actinide compounds UO2, UPt3 and UBe13. The differences in the degree of localization of the 5f-electrons in the insulating UO2 and in the metallic, heavy fermion compounds UPt3 and UBe13 are discussed. In both types of compounds we find evidence of localized electronic excitations, which yield a good fit of the magnetic susceptibility data. The spin relaxation of UPt3 and UBe13 at q ≈ 0 are determined experimentally from the quasielastic ligh scattering. © 1988.