ASCA observations of inverse-Compton (IC) X-rays from radio lobes are presented. By comparing the IC X-ray flux with the synchrotron radio flux, the electron energy density and magnetic field intensity in the radio lobes have been determined separately without a minimum energy assumption (Tashiro et al. 1998; Kaneda et al. 1995; Feigelson et al. 1995). X-ray images of Fornax A and PKS B2356-611 obtained recently with ASCA reveal positional discrepancies between Xray and radio brightness distr...