Features involved in the simulations both on continuum basis and on discrete particle basis are reviewed. It is of importance to make an attempt to carry out these two approaches and compare with experimental observations, so that we would be able to bridge the gap between the microscopic and macroscopic behaviours of particle assemblies. In the simulation by particulate modeling, an assembly of particles is compacted with various ratios of strain rate in three directions, and the constitutive.behaviour is investigated. It is thus shown that the yield surfaces agrees qualitatively well with experimental observations which have already been reported and with the ones predicted by the theories so far developed.[simulation, powder compaction, constitutive behaviour, particulate modeling]