The synthesis of nanostructured Cu2O was conducted in a non-aqueous solution via polyol method at a temperature of 130 ℃. It was found that the formation of Cu2O nanobelts was heavily dependent on the presence of surfactant cetyltrimethylammonium bromide (CTAB). Cu2O nanobelts with 100-400 nm in width and several micrometers in length were only observed when CTAB was used, whereas in other cases where CTAB was absent or CTAB was replaced with polyvinylpyrrolidone (PVP K-30), only spherical or cube-like particles were formed. The formation mechanism of Cu2O nanobelts was discussed.