Abstract：In order to estimate the excavating quality of Bakun Hydropower Station in Malaysia，confirming the supporting scheme and analyzing the rock stability，the sonic wave method is used for the loosened zone. The thickness of loosened zone and the values of dynamic deformation modulus and static deformation modulus are provided. The feasibility that the Es is obtained by the relation of Ed and Es is discussed. The distribution rule of loosened zone is analyzed. It is found that the blasting impact on loosened zone is strong，and the rock mechanical characteristics are obviously weakened and it is mainly determined by the type of rock mass.
