Abstract: In this paper,two 1/6 scale core walls including a normal reinforced concrete core wall and a reinforced concrete composite core wall with concealed steel truss were designed.The experimental study on the torsional behavior of two core walls subjected to eccentric horizontal Loading was carried out.The torsional capacity,torsional stiffness,torsional angle ductility,torsion-torsional hysteretic behavior,energy dissipation and failure mechanism of the core walls were discussed.The test results showed that the torsional performance of core walls was improved greatly by the concealed steel truss.