Metal oxide microspheres have potential applications in many fields. However, so far, the construction and controlling of nanostructures which play a crucial role in tailoring the properties of microspheres and hollow microspheres are still difficult. In this work, we were the first to successfully tune the nanostructures of spheres and hollow spheres of ZnO during a solvothermal reaction system by using imidazolium tetrafluoroborate ionic liquids. The results indicate that not only can ionic liquids be used as soft templates to provide a really facile approach for the elaboration of hierarchical nanostructures but also this solvothermal reaction system associated with ionic liquids may be regarded as a hybrid solvothermal and ionothermal system, which possesses a “two in one” advantage and hence can provide a powerful tool for the synthesis of novel materials with interesting morphologies and properties in the future.