Abstract： By X-ray CT method，it is found that rock experiences condensation，dilatancy，evolution of CT crack and rapture process in turn under uniaxial compression，which shows the meso-mechanism of rock deformation and rapture. CT image analysis and density damage increment analysis are two approaches based on X-ray CT. Through CT image analysis，the width，length and direction of crack are gained. The values of density damage at any stress state and position are gained by analysis of density damage increment. At the process of CT crack and rapture evolution，the acoustic emission can not precisely reflect the meso-mechanism of rock deformation and rapture because of localization of damage.
