Nanowires of inorganic salts (CaCO 3 , BaCO 3 , CaSO 4 ) were prepared in the nonionic surfactant reverse micelles (Triton X-100/cyclohexane/water) system. The growth process of CaCO 3 nanowire was monitored by the transmission electron microscopy (TEM) technique as a function of time. TEM images reveal that the CaCO 3 nanowires were formed in the reverse micelles by the directional aggregation process. The nanowires of CaCO 3 were 5-30nm in diameter and had a length more than 10μm.