Polycrystalline samples of Zn/sub 1-x/In/sub x/Co/sub 0.075/O (0.010/spl les/x/spl les/0.020) diluted magnetic semiconductors were prepared by the rapid oxalate decomposition technique. Phase purity is analyzed by means of X-ray diffraction technique and structures are refined by Rietveld refinement technique. Bulk conductivity of the polished pellets was measured by two-point probe technique at 295 K. Magnetic properties were analyzed with magnetic property measurement system. Samples show paramagnetic behavior and Curie-Weiss fitting at high temperature range gave effective magnetic moment of Co ions. Magnetization behavior caused by applied magnetic field was also investigated. High itinerant carrier concentration was achieved but no ferromagnetism was observed in the samples.