Size-controlled hierarchical V2O5 hollow microspheres with tunable nanoscale building blocks were synthesized using a novel solvothermal reaction in the presence of poly (vinylpyrrolidone) (PVP), and their formation mechanism was suggested. The effect of microsphere size and building block shape on the lithium storage properties was also discussed. The size of V2O5 hollow microspheres was controlled by the variation of solvothermal reaction time owing to the splitting of PVP-based micelles by the enhanced movement of chains in PVP. In addition, the morphology variation of V2O5 building blocks in V2O5 hollow microspheres from nano-cuboid to nano-platelet was achieved. The hollow V2O5 microspheres with a smaller sphere size and assembled nano-plates showed a high discharge capacity (292 mA h/g at 44.5 mA/g) and improved rate performance than that of the microspheres with a higher sphere size and assembled nano-cuboids. Such enhanced electrochemical properties of hollow V2O5 microspheres during the lithium insertion/extraction can be attributed to the improved surface area, agglomeration resistances, and short diffusion path of lithium ion in the nanoscale 2D V2O5 plates.