FeCl3-CrO3-graphite bi-intercalation compound (FeCl3-CrO3-GBC) encompassing the double FeCl3-CrO3 co-intercalation layers was examined by FTIR spectroscopy and thermal analysis. The results obtained for FeCl3-CrO3-GBC were compared to those for the binary graphite intercalation compounds: FeCl3-GIC and CrO3-GIC. In FTIR spectrum for FeCl3-CrO3-GBC the bands observed in both FeCl3-GIC and CrO3-GIC were preserved with a slight shifting and new band around 1100-1200 cm(-1) appeared. The reason for this feature is suggested to arise from the donor-acceptor interaction within FeCl3-CrO3-graphite system. Such an explanation is consistent with TG, DSC and XRD measurements.