In the present work, uniform litchi shaped cuprous oxide (Cu₂O) nanoaggregates were synthesized via a facile method by employing copper(II) chloride, sodium hydroxide, ethylene glycol and ascorbic acid in the absence of surfactants at room temperature. With further increase of the reaction temperature, broken hollow copper nanoaggregates were obtained. The structure of a Cu₂O nanoaggregate was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis and High Resolution Transmission Electron Microscopy (HRTEM). The as-obtained Cu₂O nanoaggregates showed efficient catalytic activities in the aerobic oxidative synthesis of imines.