It was observed with transmission electron microscopy in theIn0.52Al0.48As/InxGa1−xAs/In0.52Al0.48Assystem grown on the (001) InP substrate that misfit dislocation lines deviate ⟨110⟩ directions at an angle with its value depending on the gallium content. Such an abnormal alignment of misfit dislocations is explained in terms of an alloy effect on the formation of single jogs on misfit dislocations in the interface between the III–V ternary compounds. ©1998 American Institute of Physics.