The surface-enhanced Raman spectra of bilirubin and biliverdin were obtained.By the bands analysis of the spectra,the orientation of bilirubin and biliverdin on the surface of silver colloid was discussed.In such case,the bilirubin was adsorbed on the silver colloid particle with the two planar pyrromethenone groups intercalated into the globe silver colloid particle,however,the biliverdin might lie flat on the surface of silver colloid with syn-synsyn conformation.