A suspension polymerization of polymerizable monomers is conducted in a system containing an inorganic dispersion stabilizer and an inorganic pigment and/or black coloring agent, in which the polymerizable monomers have an opposite charge in water to the inorganic dispersion stabilizer whereby the former is ionically bound with the latter. The suspension polymerization during the middle stage in which polymer particles are apt to stick together is stabilized and the polymer particles are prevented from coalescing so that fine spherical polymer particles are obtained with a uniform particle size distribution.Also, the suspension polymerization is conducted having liquid resins involved in polymerizable monomers thereby to obtain non-sticky, free flowing particles. These particles adhere to paper sheets by mechanically smashing.