In this work, we presented the synthesized results of GeO2 complex composed nanostructures (nanobubbles (NBs) on sidewall of nanowires (NWs)) via the vapor liquid solid (VLS) method. By using a 20 nm of Au nano–film (AuNF) catalyst, prepared by the conventional direct current (DC) magnetron sputtering deposition method, the GeO2 NBs were randomly synthesized along the sidewall of GeO2 NW based two thermal annealing modes in vacuum–furnaces (~10−3 torr) with the diameter in the region conformed from 150 to 450 nm. Transmission electron microscopy (TEM) images indicated the different crystalline phases of NB depended on annealing temperature (T2 = 600 and 650 °C for (102) & (110) plane, respectively). Energy–dispersive x–ray (EDX) analysis results only showed oxygen (69.08%) and germanium (30.92%) of GeO2 nanobubble. Also, bright blue emission peak at wavelength of 438 nm was observed from GeO2 NB–NW–like structure at room temperature. This leads to applications of optoelectronic nanodevices. The detailed of NBs formation mechanism on NW was also discussed.