The high-pressure phase transformation of Er3+-doped Gd2O3 nanorods was studied by synchrotron radiation X-ray diffraction (XRD) and Raman scattering spectra. The starting cubic phase is stable up to about 9 GPa, and the Gd2O3/Er3+ nanorods start to transform into an amorphous phase related to monoclinic structure at 9.4 GPa. The phase transition is different from that direct crystal crystal transformation observed in the bulk Gd2O3 and Gd2O3 nanomaterials. The bulk modulus for cubic Gd2O3/Er3+ nanorods is determined to be K-0 = 196 +/- 13.4 GPa by fitting to the second-order Birch-Murnaghan equation of state, which is larger than that of 164 +/- 3 GPa of the bulk Gd2O3/Er3+. In addition, the quenched samples almost maintain their pristine nanorod shape but with amorphous form. It is proposed that the special rodike morphology and particle size probably play important roles in the high-pressure behavior of Er3+-doped Gd2O3 nanorods.