Dispersed cupfite (Cu2O) nanowhiskers were synthesized in a water/butanol/cyclohexane/cetyl trimethyl ammonium bromide (CTAB) water-in-oil microemulsion system at 25C. The nanowhiskers with a diameter of about 8 nm exhibit a well-crystallized one-dimensional (1D) structure over several hundreds nanometers in length and mainly grow along thick nanowhiskers can be prepared but they are apt to agglomerate. The possible growth mechanism of Cu2O nanowhiskers is speculated. The surfactant and the microemulsion system are related to the 1D shape formation and the even dispersion of Cu2O nanomaterials, respectively.