There are provided a composition for matte layer formation suitable for the production of a matte synthetic leather having a matte surface with a high level of jet-blackness even without the practice of embossing, raising, etc., and a release sheet for the production of a matte synthetic leather by using the composition. The composition for matte layer formation suitable for the production of a matte synthetic leather comprises a thermosetting resin and a matting agent as indispensable components. The matting agent comprises one or at least two types of organic or/and inorganic porous fine particles. The porous fine particles have a mean particle diameter in the range of 0.5 to 20 .mu.m and a specific surface area in the range of 1 to 1000 m.sup.2/g. The release sheet is produced by using the composition.