The microstructure evolution of Fe-30% Cu fine-grain composites during sintering of fine panicle blends and during heat treatment of the high-density specimens up to 1130 degreesC was investigated. The metal powder blends with particle sizes less than 0.1 mum were prepared by mechanical allowing technique. The quantitative analysis of microstructure was carried out. The microstructure of solid-state sintered composites was practically identical for all specimen treatment conditions and featured a high degree of dispersity and uniformity. Very fast coarsening of the microstructure took place at the temperature 1130 degreesC during sintering powder blends and during heating of the high-density specimens. The mechanism of microstructure transformation is discussed. The solid-state treating Fe-30% Cu materials have high hardness and good conductivity after hardening. These characteristics impair immediately when the copper liquid-phase appears.