Incorporating nano fillers such as multi-walled carbon nanotubes (MWCNTs) into polymeric matrix can generate rough surface and transfer stress directly to improve adhesion of metal-polymer interfaces. However, the interfaces became more complicate to optimize the adhesion. In this work, the effects of MWCNTs with different surface chemical groups and different diameter on surface profile, wettability and adhesion were studied. The results showed that the adhesion was related to surface wettability when using pristine MWCNTs and this relationship was extinct after the MWCNTs were functionalized. Out of the intuition, the functionalization was not with perfect universality in improving adhesion. D peaks were expanded with the I_D/I_G and FWHM of A₁ and A₄ increased by dual functionalization from 0.33 to 0.62, 92.39 to 105.91 cm⁻¹ and 0.49 to 1.63, 140.47 to 172.24 cm⁻¹, respectively. We found that the adhesion of functionalized MWCNTs depended on multiple factors including surface roughness, wettability, the intrinsic mechanical property of MWCNTs, and stress distribution on MWCNT surface when combined with the surface enhanced Raman spectroscopy (SERS) results. This work will be inspiring for novel technology of metal-polymer interfacial modification.