It is an object of the invention to provide a polymer compound that, when used in a light-emitting device, results in excellent luminance life for the obtained light-emitting device. The invention provides a polymer compound comprising a constitutional unit represented by formula (1). [In formula (1), R1A, R1B, R2A, R2B represent an unsubstituted alkyl group, R3 and R4 represented an unsubstituted or substituted alkyl group, an unsubstituted or substituted alkoxy group, an unsubstituted or substituted aryl group, an unsubstituted or substituted aryloxy group, an unsubstituted or substituted heterocyclic group, an unsubstituted or substituted silyl group, a halogen atom, an alkoxycarbonyl group, a carboxyl or a cyano group, and R5 and R6 represent an unsubstituted or substituted alkyl group, an unsubstituted or substituted alkoxy group or an unsubstituted or substituted aryl group. The letters a, b, c and d each represent an integer of 0 to 3. When multiple R3, R4, R5 and R6 groups are present, they may be the same or different.]