An experimental study on collision dynamics characteristics of big concrete block is presented. In order to obtain the recovery coefficient and contact time, a special measuring system is constructed. The experimental results show that the recovery coefficient is increased with the rise of collision velocity but the variation of contact time with collision velocity is opposite. Meanwhile the recovery coefficient of high level concrete is also larger than that of the low level. The inner damage of material in the collision recorded by AE sensors is measured and the results indicated it was the main reason that leads to the energy loss.