Abstract: A whole process digital tracking test scheme of marble meso-damage based on scanning electron microscopy（SEM) is designed for the uniaxial compression of a marble sample from Jinping,Sichuan.Based on the digital image processing technology,a quantitative analysis for the whole process of microfracture from initiation,growth to breakthrough is made,and the basic geometrical data such as area,azimuth angle and length of the sample in load-bearing process are extracted.Statistic analysis is made on the whole process meso-damage information of the micro-fractures of 32 samples by statistics theory.It is concluded that the azimuth angle,length and space of marble sample micro-fractures in the uniaxial compression process obey the regularity of generalized extreme value distribution of variable parameters.

Key words: SEM, Meso-damage quantification, Generalized extreme value distribution