- X-band (ν = 9.4 GHz) electron magnetic resonance (EMR) measurements were carried out in polycrystalline La0.4Ca0.6Mn1−xRuxO3(0 ⩽ x ⩽ 0.16) samples at 100 K ⩽ T ⩽ 550 K, aiming to study magnetic/electronic ordering induced by Ru doping. EMR indicates that such doping modifies even the paramagnetic state of La0.4Ca0.6Mn1−xRuxO3 series: the linewidth of resonance signal increases with doping. The initial charge-ordered (CO) antiferromagnetic (AFM) ground state is also drastically modified by doping. At Ru contents x ≥ 0.04, the ferromagnetic (FM) EMR signal is observed below former TCO. It evidences that the CO transition transforms into the FM one. The magnetic ground state of La0.4Ca0.6Mn1−xRuxO3 remains definitely inhomogeneous due to the coexistence of FM and AFM phases up to, at least, x = 0.10. The data obtained are compared with known ones for CaMn1−xRuxO3 system and discussed in the framework of the energy diagram model for Ru-doped manganites.