A toner for developing an electrostatic image is disclosed. The toner is composed of association of a plurality of fine polymer particles, and the total volume of pores having a diameter of not more than 0.1 .mu.m on the toner surfaces is not more than 30 percent of the total toner volume. An image forming method employing the same is also disclosed. A toner which does not result in an unstable charge amount over an extended period of use can be obtained.