Li2MnO3 ultrathin porous nanobelts with excellent continuities have been fabricated by the electrospinning method. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that Li2MnO3 was well-defined one-dimensional nanobelts. The X-ray diffraction (XRD) results exhibited that the regular belt-like nanostructures possessed high degree of crystallinity without any detectable impurity phases, while their nanoparticle counterparts prepared by a typical sol-gel route were beset by several foreign impurities. Moreover, such nanobelts also demonstrated larger surface areas compared with the nanoparticles. A temperature-dependent experiment has been adopted in an attempt to trail the growth process of the nanobelts, and then a possible formation mechanism was proposed. Finally, other lithium manganese oxides e.g. LiMn2O4 and Li4Mn5O12 nanobelts were also synthesized via simply changing the rations of Li to Mn, indicating a versatile method was introduced in this work to obtain regular nanobelts.