Poly($\alpha$-[2,5-thiophemediyl]p-(4,7,10-trioxadecoxy)benzylidene-block-$\alpha$-[2,5- thiophenequinoidmethanediyl])(PTTOBQ,$\underline{5}$) and poly($\alpha$-[3-methly-2,5- thiophenediyl]p-4(4,7,10-trioxadecoxy)benzylidene-block-$\alpha$-[3-methyl-2,5- thiophenequinoidmethanedenediyl]) (PMTTOBQ,$\underline{6}$) were polymerized with 4-hydroxybenzaldehyde and thiophenes. Their $x^{(3)}$ values were measured at 532 nm from 1 wt\% polythiophenes in 1$\mu$m polystyrene films by picosecond degenerate four wave mixing(DFWM). They were shown the $x^{(3)}=4.5\times10^{-8}$ esu for PTTOBQ($\underline{5}$) and $4.6\times10^{-9}$ esu for PMTTOBQ($\underline{6}$).