Abstract: The present invention relates to a polyester resin comprising a biomass-derived monomer and a preparation method therefor, and a powder paint composition comprising the resin and, more specifically, to a polyester resin and a preparation method therefor, and a powder paint composition comprising the resin, wherein the polyester resin comprises, as a repeat unit, a biomass-derived unit having improved reactivity and being derived from an anhydrosugar alcohol or a derivative thereof, thereby solving the problem of the depletion of petroleum resources corresponding to limited resources, exhibiting eco-friendliness and high-heat resistance, and remarkably improving weather resistance and flexibility of a coating film when used for a powder paint.