A toner for developing an electrostatic image having a good combination of hot offset resistance and low temperature fixability. The toner includes (1) a resin having at least one group that can react with a compound having an active hydrogen in an amount of 2 pieces per molecule of the resin, and a colorant. The toner satisfies the following relationship: 3.ltoreq.G=R-R.sub.ideal.ltoreq.20, where G represents a ratio of a weight of components other than the colorant and the resin that are insoluble in the organic solvent to total weight of the toner, R represents a weight ratio of components included in the toner that are insoluble in the organic solvent to the total weight of the toner, and R.sub.ideal represents an ideal weight ratio of the colorant and the resin, which is calculated from a formula of the toner.