Abstract: Based on the acoustic emission (AE) mechanics of concrete loaded at different stages,by using the AE characteristics at different stages,the relationships between parameters of AE and damage have been derived,the 1-dimensional eonstitutive relation of concrete,in which its damage parameters are expressed by AE parameters,is also obtained.Therefore,it is proPOsed that the damage degree of concrete can be evaluated and estimated by using AE characteristics.The analytical results coincide quite well with the actuality of concrete.