The surface plasmon facilitated intermolecular hydrogen bonds enhancement of fluorobromobenzaldehyde (FBB) isomers on Ag nanoparticles have been investigated by means of surface-enhanced Raman scattering (SERS). Comparing the SERS spectra and normal Raman scattering (NRS) spectra, the intensity of the O center dot center dot center dot H bending vibration peak was found to be clearly enhanced, and a new C-O peak appeared in the SERS spectrum. The C=O stretching vibration Raman spectrum reduced. We surmise that intermolecular hydrogen bonds are strengthened, due to the surface plasmon effect generated hot electrons act on the aldehyde group. Our work may promote further investigations on intra/intermolecular hydrogen-bonded chemical systems.