The plain type milling test with oxide tools added carbide has been performed on 0.53%, carbon steel at high cutting speed range. The wear patterns and the wear rates are measured together and the application of oxide tools in the plain type milling at high speed range are investigated. The important results obtained are as follows.(1) The tool life of oxide tools are superior to carbide tools at high cutting speed range. (2) The wear rates of plain type milling cutters at high cutting speed range are ruled by the flank wear of tools.(3) The flank wear rate curves with cutting speed consist of two parts.(4) In first part, the small honeycomb pattern cracks appear in the flank face a little away from the cutting edge of the tools. The small honeycomb pattern cracks grow up gradually and then the end of cracks reach the cutting edge of tools, they begin to trans-form the small groove wear. This part is called the second part of tool wear.(5) In spite of the wear rates in the second part of wear are influenced by the number of impact cycle and the temperature of cutting edge, the distractive tool failure does not occur at all.