To provide a polyester resin composition being able to maintain a long-wavelength ultraviolet-blocking effect for a long period of time, ensuring high solubility for a solvent, and having excellent light resistance. A polyester resin composition comprising a compound represented by the following formula (1) and a polyester resin: wherein each of R1a, R1b, R1c, R1d and R1e independently represents a hydrogen atom or a monovalent substituent excluding OH, at least one of the substituents represents a substituent having a positive Hammett's σp value, and the substituents may combine with each other to form a ring; and each of R1g, R1h, R1i, R1j, R1k, R1m, R1n and R1p independently represents a hydrogen atom or a monovalent substituent, and the substituents may combine with each other to form a ring.