Two-photon absorption properties of a series of symmetrically substituted stilbenes and asymmetrically substituted stilbene-type derivatives with the same conjugated length have been investigated. The effective two-photon absorption cross sections, δ_TPA, as large as 62.0 × 10⁻⁴⁸ cm⁴ s photon⁻¹ for D-π-D molecules and 48.5 × 10⁻⁴⁸ cm⁴ s photon⁻¹ for D-π-A counterparts have been observed. The effect of these two types of chromophores on the peak position of the linear absorption, one-photon fluorescence as well as two-photon absorptivity is reported. Dipole moment change between the ground and the first excited states (Δµ_ge), and the transition dipole moment between the first and second excited states (M_ee′) have also been calculated. It was found that the asymmetrically substituted derivatives possess relatively large Δµ_ge, whereas the symmetrical counterparts show an increase in M_ee′. Although a large two-photon absorption resonance is due to the simultaneously high values of M_ee′ and Δµ_ge, correlated to intramolecular charge transfer, the former function is larger. These results obtained have demonstrated that the magnitude and the peak position of two-photon absorption depend not only on the amount but also on the direction of the intramolecular charge transfer.