A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to $270^{circ}C$ from TGA thermogram with $T_g$ value obtained from DSC thermogram near $155^{circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer film at 1560 nm fundamental wavelength is $3.56{ imes}10^{-9}$ esu. Polymer 7 exhibits a thermal stability even at $5^{circ}C$ higher than $T_g$, and no significant SHG decay is observed below $160^{circ}C$, which is acceptable for nonlinear optical device applications.