Systematical　experiments　up　to　7　prestressed　composite　beams　under　positive　or　negative　moment　action　are　carried　out　in　order　to　investigate　of　the　seismic　behaviors　of　prestressed　steel-concrete　beams　under　low-cycle　loading.　The　behaviors　such　as　the　ultimate　flexural　strength,　destroy　model,　ductility　are　discussed　and　analyzed　with　the　different　parameters　of　prestressing　load,　tendon　configuration,　support　construction　type　etc.　It　can　be　valuable　for　seismic　research　and　design　of　prestressed　steel-concrete　beam.