In this paper, we propose a novel fabrication for manganese monoxide and reduced graphene oxide nanocomposite (MnO/rGO), in which microemulsion is introduced to form a 3D architecture consisting of MnO nanoparticles embedded in reduced graphene oxide network. Physical characterizations from SEM, TEM, HRTEM, XPS, Raman, and XRD, indicate that MnO particles of about 230nm are formed and uniformly embedded in rGO. Charge and discharge tests demonstrate that the resulting MnO/rGO exhibits excellent performances as anode of lithium ion battery, delivering a reversible capacity of as high as 776mAhg−1 at 1000mAg−1 after 155 cycles and rate capacity of 306mAhg−1 at 6000mAg−1 when it is evaluated in a half cell with lithium as the counter electrode.