TheYuguangbasinisahalf-grabenbasininthebasin-rangetectoniczoneinnorthwestBeijing,locatedatthenorthernendoftheShanxigrabensystem,andtheYuguangbasinsouthernmarginalfault(YBSMF)controlstheformationofthisbasin.AlinearfaultescarpmenthasformedintheproluvialfanonthepiedmontfaultzoneoftheTangshankousegmentofYBSMF.Atrenchacrossthisescarpmentrevealsthreepaleo-earthquakeeventsontwoactivefaults.Onefaultrupturedatabout9kaforthefirsttime,andthenfaultedagainatabout7.3ka,causingtheformationandsynchronousactivityofanotherfault.Finally,theyfaultedforthethirdtime,butwecannotdeterminethefaultingtimeduetothelackofrelevantsurfacedeposition.Theaccumulativeverticaldisplacementofthesethreeeventsisabout8.1m.Weestimatethattheaveragerecurrenceperiodofthepiedmontfaultisabout1.7ka,andtheaveragesliprateofthepiedmontfaultisabout1.6mm/a.Wealsoestimatethereferencemagnitudeofeacheventaccordingtotheempiricalformula.