The Coal Blending Plan for methallurgical cokemaking was optimized with the application of linear programming due to G.B. Dantzig. In this case, it was necessary to take discrimi nation in the selection of the number of the Constraints imposeed upon the system, because the number of independent variables of the optimal solution should be restricted by the characteristies of the plant facility. It was found that the optimization method was highly efficient after a series of in-plant experiments.