Gold nanocrystal(NC)/silica films are synthesized through self-assembly of water-soluble gold nanocrystal micelles and silica by sol-gel processing. Absorption and transmission spectra show a strong surface plasmon resonance absorption peak at ~520 nm. Angular excitation spectra of surface plasmon show a steep dip in the reflectivity curve at ~65° depending on the thickness and refractive index of the gold NC/silica film. A potential SPR sensor with enhanced sensitivities can be realized based on these gold NC/silica films. © 2005 Optical Society of America.