Concrete leaching experimental investigations, main influence factors during the leaching process and the leaching mechanisms are concisely reviewed, analyzed and discussed. The results show that contact leaching and penetration leaching are two major macroscopic leaching test methods. Leaching speed can be accelerated by electrochemistry or chemical reagent method and the test period can be effectively shortened. The combined utilization of the microscopic experimental methods such as CT, SEM and XRD is an effective way to investigate the leaching mechanisms for cement-based materials. Water cement ratio and water quality are the main factors of the leaching process. The concrete contact leaching is a process caused by the successive dissolution of CH, C-S-H and other compounds, with the diffusion induced by the concentration gradient. Considering the high hydraulic gradient working conditions of hydraulic structures, leaching mechanisms of hydraulic concrete under multi-factors, penetration leached hydraulic concrete models, and the cracking-fracture propagation problems of penetration leached concrete face slabs under cracking conditions need further investigation.