To obtain a thermosetting epoxy powder-coating compsn. which is excellent in finish, processibility, etc., by melt dispersing and mixing an epoxy resin, a curative, and specific fine polymer particles.

An epoxy resin having an m.p. of 50-140°C, an epoxy equivalent of 200-6,000, and an average mol.wt. of 900-10,000 is suitable. A curative which is solid at normal temp. and does not exhibit viscosity increase nor gelation in melt mixing with the resin is pref., a pref. example being a phenol resin, and pref. fine polymer particles having an average mol.wt. of 20,000-1,000,000, a glass transition point of 50-120°C, and an average particle size of 0.1-1μm, and are produced by a soap-free emulsion polymn. of a free-radical- polymerizable monomer in a water phase in the presence of a water-sol. initiator (e.g. potassium persulfate). The amt. of the curative compounded is 0.01-5wt.% of the resin when a cationic catalyst is used, and the amt. of the particles compounded is 0.1-20wt.% of the sum of the resin and curative.