Abstract: In order to study the seismic performances of steel-concrete-composite-tube (SRCT) shear walls with horizontal connections, an experiment was conducted on two full-scaled models of SRCT shear walls and a cast-in-situ RC shear wall. The results revealed that the prefabricated SRCT shear walls with the horizontal connection whether in the middle or at the botlom of shear walls all had high bearing capacity, stiffness, ductility and energy dissipation capacity. It showed the reliability of the proposed horizontal connection. Mechanical performances such as bearing capacity, stiffness and energy dissipation capacity of SRCT the shear wall with the horizontal connection in the middle of the wall were basically the same as that of SRCT shear walls without horizontal connections, and the horizontal connection had little impact on the overall seismic performances of the shear wall. Square steel tubes with tie bars could effectively restrain the cracking and crack development of concrete in steel tubes, so that the damage degree of the bases for the wall limbs the SRCT shear walls was much lower than that of the RC shear wall. Meanwhile, the internal and external concrete effectively restrained the buckling of thin-walled steel tubes. SRCT shear walls had two types of failure modes, one kind of failure could effectively make full use of strength of the material and was ideal, the other had brittle failure characteristics and should be avoided.