The high temperature deformation behavior of Cu-Al//2O//3 and Cu-TiO//2 alloy single crystals was investigated. Tensile tests were performed in the temperature range of 873-973 K. The steady-state deformation in the crystals with this orientation was observed after small amounts of deformation. The strain rate in the steady-state deformation was proportional to the stress normalized by the elastic modulus, and the stress exponents were 7-9. The activation energies for high temperature deformation were almost equal to that for self-diffusion in copper. The strain rate at a given stress increased as the particle diameter decreased and the spacing increased. The effect of the stress and the particle distribution (particle diameter and spacing) on the strain rate is discussed on the basis of the creep models so far proposed for dispersion strengthened alloys. Refs.