L-Ascorbylmonostearate was microencapsulated by a spray-drying polycondensation method with polymers such as polyvinyl alcohol, carboxymethylcellulose and polyvinylpyrrolidone, and polycondensed trimethylolmelamin trimethylether at 140°C. The particle size (1 to 10 μm) and the density (1.18 to 1.34 g/cm³) of the microcapsules increased with increasing trimethylolmelamin trimethylether content in the formulations for spray drying. The flow curve of the ointment compounded with the microcapsules under the influence of shear exhibited a thixotropic curve with a spar. The spar value and the hysteresis loop area of the curve increased with the trimethylolmelamin trimethylether content. The amount (percent) of L-ascorbylmonostearate released from the microcapsules subjected to shear stress decreased with increasing content of trimethylolmelamin trimethylether, which might strengthen the microcapsule wall. Addition of a small amount of trimethylolmelamin trimethylether to the microcapsules imparted plastic properties to them, while the addition of an excess made the microcapsules brittle. The L-ascorbyl-monostearate release rate from the microcapsules decreased with increasing trimethylolmelamin trimethylether content in the microcapsules. The drug release rates were correlated linearly with the solubilities of the polymer films prepared on a glass plate from the same formulations as used for spray drying. Polyvinyl alcohol significantly decreased the release rate. The decomposition process of L-ascorbylmonostearate in the microcapsules dispersed in water by air-oxidation followed first-order kinetics. The decomposition rate decreased with increasing trimethylolmelamin trimethylether content in the microcapsules.