Abstract: Weakly cemented rocks (WCRs) primarily comprise grains and cementing materials which were formed due to effects of compaction and cementation with the characteristics of multiscale， heterogeneity and complexity. Their macromechanical behaviors of the cemented rocks are greatly influenced by physical properties， cementation characteristics and the structural system consisting of the microscopic grains and cementing materials. In this research， an analysis idea of the macro-， and meso-， structures of WCRs is generally demonstrated. Furthermore， existing experimental techniques for researching the mesostructure of WCRs and methods of quantitatively selecting mesostructural parameters are summarized. Additionally， previous studies on the influence of single variable for mesostructural parameters on macromechanical behaviors of WCRs are also reviewed. It is proposed that the basic principles have to follow when WCRs model was established for characterizing the macrostructural evolution of WCRs； Based on this aforementioned， the evolution of grain-to-grain contact characteristics was revealed in the evolution of mesostructure for WCRs under stress state；It aims to proposing a method for extracting and determining critical characteristics of evolving mesostructure via measurement techniques， to lay a foundation for the research on the association between quantitatively measured mesostructural parameters and macromechanical behaviors of WCRs.

Key words: Weakly cemented rocks, Granular materials, Mesostructure, Critical characteristics