To study restoring force model of recycled aggregate concrete filled square steel tube column under low cycle reversed loading.The guasi-static test for six recycled aggregate concrete filled square steel tube column specimens with different replacement ratios of recycled coarse aggregate and axial compression ratios were carried out quasi-static test.The failure mode was observed

the hysteretic curves were measured.By using special method including fixed point

dropped bearing capacity of displacement amplitude and model softening point

load versus displacement restoring force model of three line was established including hysteretic curves

unloading rigidity and characteristic points such as relative yield point

relative peak point and relative failure point.It is shown that the failure modes of specimens are similar to ones of concrete filled square steel tube columns

the square steel tube is buckled at the bottom and the recycled aggregate concrete is crushed at the bottom;The hysteretic curves are plump and stable;The established restoring force model of three-line for recycled aggregate concrete filled square steel tube specimens under low cycle reversed loading agrees well with the measured hysteretic curves.So it is that suggested such model can be applied to the elastic-plastic seismic response analysis of so new type of composite structure.