Abstract: Key factors which influenced the effect of comminution by high pressure grinding rolls were described combined with the characteristics of particle-bed comminution by HPGR.The research developments of the test method and equipment selection were reviewed.Effect of comminution by HPGR was mainly affected by properties of ore，working parameters of roller press and grinding process etc.Sufficient basis for process design could be provided through small and semi-industrial comminution test of HPGR，but test process was relatively complex.Prediction of working pressure，specific energy consumption，product size distribution in particle-bed comminution could be obtained by piston press test and mathematical models.But prediction results were required to verify its applicability as well as the result of empirical formula for selection of HPGR.Development tendencies of particle-bed comminution by HPGR are fundamental research on model of efficiency of energy transform，characteristics of crushed product，effect and the simulation study of HPGR in mineral processing technology.

Key words: High pressure grinding rolls, Particle-bed comminution, Type selection test, Piston press test, Mathematical modeling