Abstract: It is a simple and efficient method to study seawater intrusion by using high density resistivity method, but it is seldom used at home and abroad. The method according to the concentration of Cl- in the water increase apparent resistivity decreases as the prerequisite of Geophysics, different geological conditions of a region in the Laizhou Bay area selected typical sections were tested, determine the Cl- to 250 mg/L of apparent resistivity values. Based on the above conditions, in Laizhou Bay area layout 16 high density electrical profiles, the success of delineation of the seawater intrusion in Laizhou Bay Area interface, indicating that the high density resistivity method as one of the seawater intrusion detection method, for environmental impact assessment, disaster management to provide technical support.