A toner for developing an electrostatic charge image which contains a polyester resin as a binder resin is provided. The toner has excellent toner properties including low temperature fixing properties, anti-blocking property and anti-offset property, etc. Also a polyester resin for a toner is provided, which is used in the above-mentioned toner. As the binder resin for toner, a polyester resin comprising (1) an aromatic dicarboxylic acid and (2) a disproportionated rosin as an acid component, and (3) a tri- or more-valent polyhydric alcohol as an alcohol component is used, wherein the molar ratio (3)/(1) of the alcohol component (3) and the acid component (1) is from 1.05 to 1.65 and the molar ratio (2)/(1) of the acid components (2) and (1) is from 0.40 to 2.60.