We have successfully fabricated the uniform porous hollow NiSe nanospheres composed of nanoparticles via a mild hydrothermal method. The growth mechanism of these hollow nanospheres was proposed based on a series of contrast experimental observations depending on different reaction conditions (including time, temperature, reactant ratio and the amount of ammonia water) as well as our understandings. We also investigated the Raman stretching modes of NiSe hollow nanospheres. Meanwhile, we have also studied the properties of magnetism and electrochemical hydrogen storage of the NiSe nanospheres. The method in our report might provide alternative synthetic approach for other metal selenides with hollow structures in the future. Copyright (c) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.