The burden distribution simulation model was indispensable so as to ensure smooth blow-in and stable operation with high productivity of Keihin No. 1 blast furnace, which is one of the largest blast furnace with bell-less top. For this purpose, basic factors governing the burden distribution in the bell-less top for a large blast furnace were examined through the 1/10 scale model experiment on the basis of the burden distribution simulation model formerly developed for Fukuyama No. 2 blast furnace. By incorporating these results and considering the particle size change during discharge, a burden distribution simulation model suitable for Keihin No. 1 blast furnace was newly constructed. It has been applied for the operation of Keihin No. 1 blast furnace. As a result, a productivity of 1.9 t/d·m3 was achieved in only two weeks after blow-in. Further use of this burden distribution simulation model has permitted stable continuation of high-productivity of 11000 t/d for a period of about a year.