A system for measuring electrical resistivity survey checks a border of bedrock or a thickness of a sedimentary layer in a riverbed of a river or lake within a short time. A method for analysis of an underground structure of a riverbed using the same is also provided. The system for streamer electric resistivity survey using a survey boat includes a streamer cable connected to the survey boat and having a plurality of electrodes attached thereto, a multi-channel resistivity meter loaded on the survey boat to measure electric resistivity from the plurality of electrodes, a first RTK GPS (Real Time Kinematic Global Positioning System) loaded on the survey boat to measure a position of the survey boat in real time, and a second RTK GPS installed to a tail of the streamer cable to measure a position of the tail in real time.