A toner for development of electrostatic images, comprising colored particles and an external additive, wherein the colored particles has a volume average particle diameter of 3 to 10 .mu.m and an average circularity of 0.950 to 0.995, and in a molecular weight distribution of THF-soluble matter, which is obtained by filtering a dispersion liquid prepared by stirring the toner in THF, by GPC measurement, a peak area a of a molecular weight range of 500,000 to 5,000,000 is 5 to 15% based on the peak area of the whole range, a peak area b of a molecular weight range of 500,000 to 5,000,000 of tetrahydrofuran-soluble matter, which is obtained by filtering a dispersion liquid prepared by further subjecting the above dispersion liquid to an ultrasonic treatment, is 1 to 10% based on the peak area of the whole range, and the peak area a and the peak area b satisfy the relationship of 0.ltoreq.a-b.ltoreq.5.