Abstract: [Problem] Provision of sustained release microparticles having excellent characteristics, in which the microparticles for supporting a substance or substances can fully control the release of the supported substances, can sufficiently diffuse the supported substances in a medium such as water, and can effect sustained release of more than one kind of the supported substances differing in water solubility, each at the respectively desired rate; and also to provide preparations which contain said sustained release microparticles. [Means of Solution] Sustained release microparticles comprising a supported substance, microgranular form and coating agent, said microgranular form having an average particle size within a range of from 20 to 300 ?m; and preparations which contain the sustained release microparticles.