Disclosed herein a process for producing a microcapsule having an excellent solvent-resistance and a thermal stability, and an extremely minute amount of unreacted formaldehyde, comprising the steps of dispersing a substance to be encapsulated into an aqueous solution containing a water-soluble cationic urea resin, at least one prepolymer selected from the group consisting of a melamine-formaldehyde prepolymer, a urea-formaldehyde prepolymer and a melamine-urea-formaldehyde prepolymer and an anionic surfactant and then, adding an acid-catalyst into the thus obtained aqueous dispersion thereby forming a wall membrane which encapsulates the dispersed microparticle of the substance to be encapsulated by polycondensing the prepolymer and the cationic urea resin followed by cross-linking while causing complex coacervation, and adding a monosaccharide into the aqueous dispersion while adjusting the pH of the aqueous dispersion with the addition of a hydroxide of an alkaline earth metal thereby removing the unreacted residual formaldehyde remaining in the aqueous dispersion.