We have demonstrated the coupling of metasurface resonance with a molecular vibration from weak to strong. Metal-insulator-metal (MIM) metasurfaces using various polymers as the insulator layer (I-layer) were fabricated and characterised. The strength of coupling between MIM metasurface and molecular absorbance in the I-layer of organic nano-film depends on the dipole mode of the molecular vibration and the molecular number density. In the case of strong coupling, when Rabi-splitting is observed at the molecular absorption band, the coupling efficiency reaches several percent of the particular molecular vibration modes in the volume below nanodisks of the MIM metasurface.