Charge-transfer (CT) interactions of tetrathiafulvalene (TTF)-based Langmuir-Blodgett (LB) films with non-centrosymmetrical structure were examined from the viewpoint of nonlinear optics. Five kinds of LB films of CT complexes were prepared using TTF-based electron donors and accepters of 7,7,8,8-tetracyanoquinodimethane and p-benzoquinone derivatives. The difference of the dipole moments between ground and excited states of these LB films was evaluated from the measurements of electroabsorption spectra.