To　improve　the　seismic　performance　of　the　RC　core　walls,　reinforced　concrete　composite　core　walls　with　concealed　steel　truss　were　proposed　and　systemically　investigated.　Two　1/6　scale　core　walls　specimens,　including　a　normal　reinforced　concrete　core　walls　and　a　reinforced　concrete　composite　core　walls　with　concealed　steel　truss,　were　designed.　The　experimental　research　on　seismic　performance　under　cyclic　loading　was　carried　out.　The　load-carrying　capacity,　stiffness,　ductility,　hysteretic　behavior　and　energy　dissipation　of　the　core　walls　were　discussed.　The　test　results　showed　that　the　seismic　performance　of　core　walls　was　improved　greatly　by　the　concealed　steel　truss.　And　the　calculating　results　were　found　to　agree　well　with　the　actual　measured　ones.