A series of water-soluble polyparacyclophanes bearing two diphenylmethane or two diphenyl ether skeletons were investigated to develop useful host compounds by using 1-anilinonaphthalene-6-sulfonate (ANS) and 2-ρ-toluidinylnaphthalene-6-sulfonate (TNS) as fluorescent hydrophobic substrates in aqueous solution. It was noteworthy that remarkable fluorescent enhancements and blue shifts of ANS and TNS were observed only in the presence of 1,6,20,25-tetraaza[6.1.6.1] paracyclophane (CPM 44) and 1,6,21,27-tetraaza [7.1.7.1] paracyclophane (CPM 55) for diphenylmethane skeleton, and 1,7,21,27-tetraaza-14,34-dioxa [7.1.7.1] paracyclophane (CPE 55) and 1,8,22,29-tetraaza-15,36-dioxa [8.1.8.1] paracyclophane (CPE 66) for diphenyl ether skeleton, comparing with α- and β-cyclodextrins. However, their acyclic analogues such as 4,4`-dimethylaminodiphenyl-methane and 4,4`-dimethylaminodiphenyl ether, and paracyclophanes whose cavities were smaller showed only small effects under the same conditions. These facts suggested that hosts and substrates were in an intimate contact which would not occur without larger structures, and thus that guest molecules were strongly incorporated in the hydrophobic cavities of these larger paracyclophanes. The effects of pH on the fluorescent intensity of ANS-CPM 44, ANS-CPM 55, ANS-CPE 55, ANS-CPE 66, TNS-CPM 44, TNS-CPM 55, TNS-CPE 55 and TNS-CPE 66 systems were not significant below pH 2.0, but their fluorescent intensities were markedly reduced with increasing ionic strength.