Samples of copper powder was milled with varied grinding frequencies in the presence of various organic agents (oleylamine, ethylene glycol or dimethyl sulfoxide) or without additives. The effects of experimental conditions were investigated by X-ray diffractometry, scanning electron microscopy and dynamic light scattering measurements. The aggregation of particles were supressed by added organics. The catalytic activities of the variously treated samples were measured in the Ullmanntype reaction of iodobenzene and 1H-pyrazole.