Abstract: To test the bulging movement laws in blasting crater tests of spherical charge, a set of cement mortar model that could simulate rock soil well was produced to make blasting crater tests. The bulging movement on the free surface centre was recorded using high speed photography system, bulging movement contour lines, bulge center velocity distribution and displacement distribution were obtained. The results indicate that bulge center velocity distribution presents a characterisitic property of acceleration-uniform-accderation-decekeratuibm after bulge center displacement inocreases to 1.5 times burden length, projectiles threw according to ballistic motion laws.