The resorcin[4]arene host compound 2,8,14,20-tetrapentadecylpentacyclo [19.3.1.1.(3,7)1.(9,13)1(15,19)] octacosa1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,6,10, 12,16,18,22,24-octol (1) has been shown to form charge-transfer complexes with a series of electron acceptors including [60]- and [70]fullerenes, and from the trends in CT transition energies the vertical ionization potential of 1 has been estimated (7.62 eV). By the UV-vis spectrophotometric method it has been shown that 1 forms an inclusion complex of 2(resorcinarene):1(fullerene) stoichiometry besides showing CT absoption bands. On the other hand, 1 does not include [70]fullerene and forms with it a simple CT type of molecular complex. This has been established by determining formation constants and enthalpies and entropies of complexation. It has been shown that inclusion of [60]fullerene is a predominantly entropy-driven process.