Nanocrystals of LaFeO3 with mean grain diameters of 12.4, 12.6, 14.4, 16.0 and 16.3 nm were compacted into pellets under static pressure of 0.5, 1.0 and 1.5 GPa in the axial direction at room temperature. Their EPR spectra change with grain sizes and compacted pressures. The results show that the g values increase a little with the increment of compacted pressures, whereas the peak intensities of EPR spectra of nanocrystalline materials are about 10(3) times as strong as those of conventional materials. This paper discusses characteristics of EPR spectra of nanocrystalline composite oxide LaFeO3.