A hydrothermal method combining a calcination process was conducted to synthesize nickel sulphate(NiS)hierarchical architectureswithcontrollablemorphologiesandsizes.First,severalhollowNiShierarchicalarchitectures assembled by NiSnanosheets had been synthesized through the solvothermal method. The nucleationmediated mechanism overwhelmingly determined the morphology of hollowNiSarchitectures through tuning the nucleation rate. The NiSspheres could be formed in the case of high nucleation rate. However, NiS hierarchical architecture could be obtained from the precursor without changing their morphologies by a simple calcination procedure.