Abstract: In this paper, to research the crack propagation and AE behavior of rock mass, an uniaxial compression text was conducted on the sandstone samples by using the servo-controlled testing machine and AE monitoring system. Meanwhile, a numerical simulation was carried out with the rock failure process analysis system, while the numerial results displayed a good consistency with the experimental results. On this basis, the influences of material heterogeneity on crack propagation were further studied by using multiple repeated simulation. The results show that the crack propagation of sandstone is greatly related to the heterogeneity of rock material. The main crack of the sandstone sample initiates from the end of pre-exiting crack firstly, and expands along the perpendicular of pre-exiting crack. Then the development of crack turned towards the loading direction，whereas, lately, the cracks on the samples grow in different directions whilst the length and speed of crack propagation are various at different stages. Moreover, the secondary crack parameters including secondary crack number, length, width and expanding direction are different.

Key words: rock mechanics, sandstone, flaws, heterogeneity, AE, crack propagation