A polymer compound which is useful for producing a light emitting device having excellent luminance life is described. The polymer compound contains a constitutional unit having a residue of a compound represented by the formula (1) and a constitutional unit having no residue of a compound represented by the formula (1): In formula (1), Ring A, Ring B and Ring C represent an aromatic hydrocarbon ring, X represents a boron atom, Y1, Y2 and Y3 represent N-Ry, a sulfur atom or a selenium atom, Ry represents a hydrogen atom, an aryl group, a monovalent heterocyclic group or an alkyl group, and n3 is 0 or 1. When n3 is 0, —Y3— is absent.