Abstract: A powdered leather which is composed of at least 85% by weight of cortex, at most 2% by weight of oil and fat, and at most 0.5% by weight of Na.sup.+ and Ca.sup.2+ ions capable of being eluted by water and which has an average particle size (D.sub.50) of at most 7 .mu.m, a standard deviation of the average particle size being at most 3 .mu.m. With this powdered leather, it is possible to thin films, coatings, fibers, etc. which would hardly be deteriorated with time.

Abstract: A rubber composition containing a powdered leather of a dispersion mixture comprising from 10 to 400 parts by weight of a powdered leather with a skin component of greater than 75% by weight, a total amount of Na.sup.+ ions and Ca.sup.2+ ions extractable with water of less than 0.5% by weight and an average grain size D.sub.50 of from 10 .mu.m to 250 .mu.m, and 100 parts by weight of rubber obtained from a raw material for the powdered leather by performing coarse pulverization, water washing, dewatering, steams swelling, drying and powderization and then separation into particles of a desired average grain size depending on the purpose of use, as well as a molding product obtained from the rubber composition.