Abstract: On account of the special quality of motion granular mass and the second loosening,the author firstly set up the volume continuum equation and the volume totle-flow continuum equation of motion granular mass that two equations stand in together on the base of tests and analysis in theory,and pointed out two equations above can be applied to verify the velocity equation of motion granular mass.The relation between velocity and volume change of motion granular mass is established by the volume continuum equation,it can be available to further study the density field of motion granular mass as weel.