Discrete element method (DEM) was applied to charging process in iron ore sintering and vertical size segregation in the feed bed was anlyized, where a particular charactor of sintering feed, plastisity and stikiness, was expressed by adjusting the rolling friction coefficient to fit a result from a preliminary test on sintering feed flowing out of a box. DEM simulations and comparison with plant data gave the following findings:1) When the rolling coefficient was 4.0, the calculation resembled the experiment in terms of the angle and the spread of feed after resting.2) The simulation for a charging apparatus recreated vertical size segregation in feed bed in good agreement with plant data.3) The simulation showed that the size segregation increased with decreasing chute angle, the change of which was explained with the fact that the horizontal velosity of particle at the bottom end of the chute also increased unless the feed made a build-up on the chute.