Abstract: Four core steel reinforced concrete (CSRC) joints were tested under cyclic loadings to investigate the effect of truncation and embedded details of core steel to the deformation performance of the specimens. The main parameters are axial compression ratio and the truncation and embedded details of core steel in a joint core. The effect of these parameters on the strength, stiffness, ductility and the hysteretic behaviour of CSRC joints are investigated based on test results. Based on the analysis of the test data on the global deformation of CSRC joints and the local deformation in a plastic zone and a joint core, the flexural deformation of a beam, the shear deformation of a joint core and the flexural deformation of a column to global deformation of the frame as well as their regularities are investigated. It is indicated that the truncation and embedded details of core steel had no obvious negative effect on the seismic behaviour of the specimens. The shear deformation of a joint core is increased because of the truncation and embedded details of core steel. The specimens with the two truncation and embedded details of core steel have almost same shear deformation of a joint core. This paper can be referenced by the nonlinear static pushover analysis of CSRC structures.