The present invention relates to a process for preparing an aqueous dispersion of microparticles containing a water-insoluble, solid, non-polymeric, organic active or functional material (M) and an aminoplast resin (A) which surrounds or embeds material (M), which comprises the following steps: i) providing an aqueous slurry of the material (M) in the form of coarse particles； ii) subjecting the aqueous slurry to shear forces such that the coarse particles of the material (M) are comminuted and an aqueous suspension of fine particles of the material (M) is obtained； iii) performing a polycondensation of an aminoplast pre-condensate during step (ii) or in the aqueous suspension of the fine particles of the material (M) obtained in step (ii)； wherein step (ii) is performed in the presence of at least one protective colloid and in the presence of at least a portion of the aminoplast pre-condensate subjected to the polycondensation of step (iii).
