Stringer runout is a key detail feature of the wing box lower panel. In this paper, static tension tests of the stringer runout structure for a trunk liner have been done to explore not only the typical failure mode and mechanical behavior of the stringer runout structure but also the difference among stringer runouts with different chamfer angle of 15°,30°and 45°。The results show that the structure fails by skin shear at the section of the first fastener. Local bending at the chamfer area is confirmed by the strain analysis. The test piece with 30°chamfer angle behaved best with maximum failure load and minimum local bending rate. The results provide the basis for the detail design of the lower panel stringer runout structure of the trunk liner.