Nanowires of inorganic salts (CaCO3, BaCO3, CaSO4) were prepared in the nonionic surfactant reverse micelles (Triton X-100/cyclohexane/water) system. The growth process of CaCO3 nanowire was monitored by the transmission electron microscopy (TEM) technique as a function of time. TEM images reveal that the CaCO3 nanowires were formed in the reverse micelles by the directional aggregation process. The nanowires of CaCO3 were 5-30 nm in diameter and had a length more than 10 mum. (C) 2002 Elsevier Science B.V. All rights reserved.