1,3,5-Tricyano-2,4,6-tris[2-(thiophen-2-yl)vinyl]benzene derivatives have been synthesized as a new type of octupolar nonlinear optical molecules and their linear and nonlinear optical properties were determined. The λmax values increa sed with the conjugation length and as the conjugation bridge was changed from phenyl to thienyl group. For phenyl and thiophene derivatives, the b value increased with conjugation length. In contrast, the $eta$ values of the thiophene derivatives were much smaller than the corresponding phenyl derivatives.