Abstract: Several Quaternary faults have been found in the Yangtze River estuary by high resolution multi-trace seismic surveying. These faults thrust into the bottom of the Quaternary period or the middle Pleistocene series, even reach the late Pleistocene series. These faults might have the close relationship with earthquake activity indicated by the study of the regional earthquake history and the latest earthquake record. Among the faults,fault F₁₂thrusting into bottom of the late Pleistocene series is close to the earthquake epicenter of MS6.1 on November 9, 1996 and MS6 3/4 on October 19, 1505. The faults might have very close relationship with the two earthquakes. These cases show that the Quaternary faults are the result of Neotectonic movement.