Abstract：A series of dynamic compression，tension and shear tests were conducted on the Bukit Timah granite of Singapore. The results are analyzed in an effort to examine the validity and the applicability of the Hoek-Brown and Mohr-Coulomb criteria for rock material under dynamic compression. It is indicated that the rock strength can be approximately described by the Mohr-Coulomb criterion at low confining pressure. The change of strength with loading rate is primarily due to the variation of cohesion with loading rate. The dynamic compression strengths are more accorded with the Hoek-Brown criterion，especially under higher confining pressure(higher than 100 MPa).
