Conformational changes of amide cavitands A-C were investigated at varied temperatures and in several solvents. While cavitands A and B, with comparatively smaller substituents such as Et and Pr-i, were always in vase conformation in non-polar solvents such as CDCl3, CD2Cl2, (D-8)THF, and C6D6, their thermoswitching (vase to kite) was observed in polar solvents such as (D-7)DMF and (D-6)DMSO or in the presence of acid (TFA) and H-bonding inhibitor (TFE). Intra- and interannular H-bonds of A and B were clearly observed by low-temperature H-1-NMR spectra in CDCl3. No conformational change of cavitand C with bigger substituent (Bu-t) was observed under any tested temperature range and in polar or non-polar solvents; C was always in the kite conformation.