The present invention aims to provide a resin composition for toners which enables to obtain a toner having excellent low temperature fixability and high temperature offset resistance, and a toner. The resin composition for toners is obtained by reacting a mixture of a branched polyester (A) having a number average molecular weight of 2,000 to 7,000 and a hydroxyl value of 20 to 80, and a low molecular weight linear polyester (B) having a number average molecular weight of 2,000 to 5,000 and a hydroxyl number of 20 to 55, with an isocyanate compound containing two or more isocyanate groups in one molecule, which comprises a crosslinked structure of said branched polyester (A), a structure in which said branched polyester (A) and said low molecular weight linear polyester (B) are bonded by said isocyanate compound, and an unreacted portion of said low molecular weight linear polyester (B).