A promoter for a polycondensation reaction used together with a catalyst in a polycondensation reaction, the promoter for a polycondensation reaction comprising a pyrogallol compound having a benzene ring of which three hydrogen atoms adjacent to each other are substituted by hydroxyl groups; and a polycondensation resin obtained by polycondensing raw material monomers using the promoter as defined above and the catalyst. A polycondensation resin can be produced using the promoter of the present invention together with a catalyst in a polycondensation reaction, and the polycondensation resin can be used in various applications including, for example, films, sheets, fibers, toner materials for electrophotography, and the like.