///Electrical resistivity tomography (ERT) has been widely applied in hydrology during recent years with its high efficiency and precision. Based on summarizing and analyzing the huge number of bibliographies, the authors discuss the complicated factors that affect the electrical resistivity underground, the relationship between the resisitivity and hydraulic parameters, the application of ERT on water resource surveying, the solute transportation monitoring and hydraulic parameters inversion. Then, the authors supply some suggestions for improving the application of ERT.