Hydrophilic silver and gold nano-colloids were synthesized using sodium oleate as a stabilizer, and their hydrophobic nano-colloids were further obtained using tetradecanethiol as a co-stabilizer and using concentrated hydrogen chloride acid as an initiator. UV-visible spectra of the gold and silver nanoparticles at different states were recorded and compared. The spectra show that surfactant stabilized colloids are stable and monodispersed both in aqueous solution and in organic solvents. Surface pressure (pi)-area (A) curves of the nanoparticulate monolayers were measured and their LB films were constructed. IR spectra show that polar head group of the oleate was adsorbed on the surface of the nanoparticles.