Very recently, the investigation of an Li atom doped effect on the through-space electronic interaction (S) of a donor-S-acceptor (D-S-A, 1) shows that the Li-doping effect can modulate the first hyperpolarizability of 1 ( Dyes Pigm. 2014, 106, 7-13). Can we further enhance the first hyperpolarizability (beta(tot)) of 1 by modulating the charge transfer of D-S-A molecules? The present work indicates that the beta(tot) value can be successfully modulated by replacing the sp2-hybridized CH-CH moiety connected with substituted para-cyclophane (PCP). On the other hand, the NO2 contributes more than NH2 to the beta(tot) value. The results of time-dependent density functional theory (TD-DFT) provide a good explanation for the variation in the beta(tot) value. Interestingly, the beta tot value of 3 (4.09 x 10(3) au) is larger than 1.52 x 10(3) au of 4, while the difference between the dipole moments (Delta mu) of the ground state and the crucial excited state of 3 (2.93 D) is smaller than that of 4 (7.79 D). Further, the charge-transfer excitation length (DCT) of 3 (1.41 angstrom) is smaller than that of 4 (2.89 angstrom). Therefore, DCT is the major factor in determining the Delta mu value.