The fabrication of manganese oxide-carbon composite microspheres with open nanochannels and their electrochemical performance as anode materials for lithium ion batteries are investigated. Amorphous-like Mn3O4 nanoparticles embedded in a carbon matrix with three-dimensional channels are fabricated by one-pot spray pyrolysis. The electrochemical properties of the Mn3O4 nanopowders are also compared with those of the Mn3O4-C composite microspheres possessing macropores resembling ant-cave networks. The discharge capacity of the Mn3O4-C composite microspheres at a current density of 500 mA g(-1) is 622 mA h g(-1) after 700 cycles. However, the discharge capacity of the Mn3O4 nanopowders is as low as 219 mA h g(-1) after 100 cycles. The Mn3O4-C composite microspheres with structural advantages and high electrical conductivity have higher initial discharge and charge capacities and better cycling and rate performances compared to those of the Mn3O4 nanopowders.