In order to study the relationships between the chemical structures of polymer main chains and second order nonlinear optical properties, novel polymers with hexa-2,4-diynylene-1,6-dioxynaphthoate as a main chain and common azo dyes (Disperse Red 1 and 13) in the side chains, were synthesized and characterized. The polymers were soluble in common organic solvents such as chloroform, dimethylformamide, N-methylpyrrolidone, etc, and gave films with excellent optical quality by spin coating. Apparent orientation parameters of around 0.25 were observed by the absorption decrease by Corona poling. The steric effect of chlorine atom of the dye on poling was not observed. On heating at 100 °C after poling the order parameters did not return to zero but reached a constant. It is thought that some of the chromophores remain orientated permanently.