In this paper, the behaviour on tapered joint panels in RHS column to beam connection is investigated. A series of tests are carried out to investigate the elastic plastic behaviour on tapered joint panels using connection subassembrages subjected to static cyclic lateral load corresponding to seismic loads. The variables of the tests are as follows: (1) configurations of the joint panel, (2) difference between upper column width and lower one, (3) magnitude of axial force in column. Also numerical calculations using elastic plastic finite element method are performed to examine the stress and strain distribution in elastic plastic region. The following results are concluded: 1) The elastic shear rigidity of tapered joint panel is larger than that of non-tapered joint panel which has the same width of upper column in the tapered joint panel, and smaller than that of non-tapered joint panel which has the same width of lower column in the tapered joint panel. 2) The yield shear strength of the tapered joint panels is determined by the upper panel area independent of the difference in width of upper panel and lower panel.
