New synthetic route and characterization of alkyl-capped nanocrystalline silicon (R-n-Si) were achieved from the reaction of silicon tetrachloride with sodium/benzophenone ketal reducing agent followed by n-butyllithium. Surface of silicon nanoparticles was derivatized with butyl group. Effect of oxidation of silicon nanoparticle with benzophenone was investigated for their stabilization. Optical characteristics of silicon nanoparticles were characterized by fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), and photoluminescence (PL) spectroscopy. Butyl-capped silicon nanoparticles exhibited an emission band at 410 nm with excitation wavelength of 360 nm. Average size of n-butyl-capped silicon nanoparticles was obtained by particle size analyzer (PSA) and transmission electron microscopy (TEM). Average size of n-butyl-capped Si nanoparticles was about 6.5 nm.