The load-unload response ratio (LURR) reflects the damage evolution of rocks and, thus, is a good way to describe rock stability. With the background of stopping in a metal mine, this paper studies the relationship between LURR and damage of brittle rocks. Based on the elasto-brittle damage theory, the analytical expressions of LURR were first derived for brittle rocks under both uniaxial and conventional triaxial loading/unloading conditions. Then, uniaxial and conventional triaxial loading/unloading tests were conducted on brittle rocks. The experimental results indicate that the LURR varies greatly at the initial stage, possibly due to the compaction and heterogeneity of rock. As the load increases, the LURR keeps almost constant with occasional fluctuation, possibly due to propagation of local cracks. When the rock is close to failure, the LURR presents abrupt increase or great fluctuation. The experimental results are in reasonable agreement with the derived analytical expressions of LURR.