Nanoarchitectures consisting of single crystalline Co3O4 spheres and multi-walled carbon nanotubes (MWCNTs) have been constructed successfully. The effect of reaction temperature on the morphology of the products reveal that the growth rate dictates the shape and size of Co3O4 beads on and around MWCNTs. Single crystalline Co3O4 spheres around MWCNTs can be produced in large scale by elevating reaction temperature for the increased growth rate. The electrochemical properties of the hybrid materials were investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. The supercapacitors made with the nanoarchitectures show high specific capacitance of 445 F/g at a current density of 0.1 A/g and exhibit excellent cycling stability.