To provide a lubricant for hot plastic working which is excellent in lubricating properties, feedability and operability and will produce no adverse affects on the corrosion resistance of the products.A lubricant for hot plastic working which is characterized in that the composition is comprised of, in an anhydrous condition, 50 to 80% by mass of iron oxide, 20 to 50% by mass of sodium silicate and 1 to 20% by mass of calcium oxide and that the total content of the impurities of zinc oxide, lead oxide and copper oxide is not higher than 5% by mass, where the content of the stabilizer is not counted. This lubricant is suited for use in lubricating guide shoes in piercing-rolling of high-Cr steel species.