Abstract: Allusion to the crack of concrete, the authors studied on GT anti-cracking agent to improve the character of anti-cracking or release the crack of the concrete. GT anti-cracking agent is a novel concrete anticracking agent made of CSA high efficiency expansive agent and polymer at a certain ratio. Experiments have been done to investigate the anti-cracking related properties such as the mechanical properties, shrinkage, expansion, early age shrinkage of the mortar specimens with the addition of GT anti-cracking agent. The results demonstrat that GT anti-cracking agent is an optimistic anti-cracking material and has a remarkable effect on suooressing the cracks of cement mortar.