In a method of developing a electrostatic charge pattern in which a magnetic brush is formed by supplying a developer consisting of a magnetic carrier and a magnetic toner onto a non-magnetic sleeve disposed so as to face an image carrier surface and incorporating a magnetic field producing member, the magnetic toner contains 25 to 60% by weight of a magnetic powder and the coercive force of the magnetic toner is not greater than 60 Oe. Preferably, the coercive force of the magnetic toner is not smaller than 15 Oe. The magnetic toner is composed, of, for example, styrene.sub.n -butylacrylate copolymer, magnetite and a charge control agent.