Dispersal agents can increase the surface interaction between SWCNTs and water via coating themselves on the surfaces of SWCNTs, thus to solubilize and disperse SWCNTs in water. In this study, we have used γ-cyclodextrins (γ-CDs) to solubilize SWCNTs in water. A dark SWCNT-water colloidal suspension has been formed, while the system of SWCNTs alone in water looks like clear water with black precipitates. AFM images of SWCNTs prepared from the colloidal solution with γ-CDs clearly showed that γ-CD molecules decorated the surface of each SWCNT with a height around 4 nm. The images (in the same scanning range) also contain more SWCNTs than the ones of the SWCNTs alone (~ 18 nm in height, as a bundle structure). Force-distance curves (FDCs) have been measured to further probe the interaction between SWCNTs and γ-CDs. Molecular dynamics (MD) simulation has also been performed for understanding such interaction.