With the actual threedimension element, the nonlinear finite element analytic models were established for boltweld joints between square concretefilled tubular (CFT) column and reduced beam section with inner separates, considering geometric large deformation, materials nonlinear and contact nonlinear. Compared with finite element model and experimental model, it was in good agreement in principle. And the characteristics of loaddisplacement(PΔ) curves, the stresses distribution of beam, the dissipating energy ability and destruction form were made with numerical analysis for bearing behavior of boltweld joints between square CFT column and reduced beam section . It was shown that the initial stiffness of joint with reduced beam section was close to that of nonreduced beam section joint. The bearing capacities of joints with reduced beam section were a little bit lower than those of nonreduced beam section joint. The plastic hinge in the joint with reduced beam section moved to the reduced beam region. The studied joints displayed a better ductility, energy dissipation and good seismic behavior.