Single-walled carbon nanotubes (SWNTs) were functionalized with amphiphilic octadecylamine (ODA), and the solubility of SWNTs in chloroform was largely enhanced. The surface pressure-area isotherm indicated good spreading properties of functionalized SWNTs. According to scanning electron microscopy (SEM) images, highly ordered in-plane orientation of SWNT films was achieved by Langmuir–Blodgett (LB) technique at room temperature. The distance between the aligned SWNTs decreased with increasing surface pressure. Homogeneous multilayers were obtained via layer-by-layer deposition. The current-voltage (I-V) characteristics of multilayer films were investigated, in which the SWNTs were aligned perpendicularly and parallel to the electrodes, respectively.