Kinetic studies of the deacylation reactions of p-and m-nitrophenyl esters of (R or S)-${alpha}$ -methoxyphenylacetic acid were performed in ${eta}$ -CD, mono-6-deoxy-6-[N-(2-aminoethyl)]amino-${eta}$-CD (${eta}$-CDen) and mono-6-deoxy-6-[N-(2-aminoethyl)-2-aminoethyl] amino-${eta}$-CD (${eta}$-CDdien) media. The binding constants (K) of the substrates to the hosts and the rate constants ($k_{varphi}^{CD}$) for the complexed substrates were determined. $k_{varphi}^{CD}$ values are highly dependent on the hosts and the substrates, whereas differences in K values among them are modest. The p-nitrophenyl esters show larger acceleration by -${eta}$-CDen and -${eta}$-CDdien than the corresponding m-isomers, while the m-isomers are more reactive than the p-isomers in -${eta}$-CD media. This is taken as an indication that the amino groups attached to the primary side of -${eta}$-CD participate in the deacylation reaction.