A toner and a resin for toner are provided which are of good low-temperature fixing ability and good anti-blocking property of toner at high temperature and high humidity and good pulverisability. The present invention is directed to a resin for toner, the resin comprising a polyester resin (A) produced by reacting a polyester resin (a) having an acid value of 6 mgKOH/g or less and a hydroxyl value of 10 to 80 mgKOH/g with at least one carboxylic acid (b) selected from the group consisting of aliphatic carboxylic acids, aromatic carboxylic acids, their anhydrides and lower alkyl (C1-C4) esters, wherein the equivalent ratio OHa/COOHb is 0.55 to 1.0 where OHa represents the equivalent of the hydroxyl groups originating in (a) in the reaction of (a) and (b) and COOHb represents the equivalent of the carboxyl groups originating in (b) in the reaction of (a) and (b), and wherein the polyester resin (A) has an acid value of 13 to 50 mgKOH/g and a hydroxyl value of 8 mgKOH/g or less; and a toner composition including the same.