Abstract: The paper reviews the studies of fatigue of concrete with a logical perspective focusing on the internal mechanism. It is shown that the existing researches can be classified into three main types: the phenomenon models based on fatigue tests, the fatigue crack propagation models based on fracture mechanics and the fatigue damage evolution models based on damage mechanics. The main features of each kind of models are summarized. Further, it is suggested that the rate process theory can explain the physical foundation of fatigue of concrete from the viewport of reductionism. In view of the considerable scatters in the results of concrete fatigue tests, the concept of the physical stochastic system is proposed.