The loading velocity has powerful influence on rock’s acoustic emission(AE).Based on AE signal acquired by uniaxial compression experiment of griotte and red sandstone under different loading velocities,the time series parameters of the AE signal was calculated,and the relationship between AE signal and loading velocity was got.The results showed that the characteristics of AE signal was obvious different under different loading velocities,with the of loading velocity increasing,the energy rate and hit rate were becoming bigger,however the summation of energy and hit were becoming lower.Loading velocity also has a certain influence on the failure mode of rock,higher loading velocity is,more intense the damage of rock is.