O+, He+, and H+ ions in the energy range 0.5 to 16 keV have been observed in the storm-time ring current with an energetic ion mass spectrometer aboard the polar-orbiting S3-3 satellite. During the main phases of the 29 December 1976, 6 April 1977, and 19 April 1977 magnetic storms, the O+ number density within the instrument energy range in the inner ring current (L=2.8--4.0) was larger than the H+ density in the altitude range from about 5000--7000 km. At two days after the main phase of the 29 December 1976 storm, O+ was still the dominant ion at MLT=14.5 hours in the L=2.6--3.4 range at altitudes near 6000 km.