Abstract: A novel combined joint design principle at stringer run-outs in stiffened composite panels was studied with reducing bond-line configurations to improve the structural debond load. FEM verified by experiment results was used to analyze load transferred and failure mechanisms of combined joint at stringer run-outs, and research the influence of bond-line length to stringer terminations debond load. The results illustrate that normal constraint and shear load path provided by fasteners in the novel combined joint concept can improve structural debond load significantly, and enhance the capacity of arresting damage propagation at the bond-line tip. Moreover, the debond load increases with bond-line configurations reducing, interface failure can be avoided while the bond-line tip is beyond fasteners in the last row, and the failure load is determined by the strength of skin mechanically joints.