AbstractThree-dimensional atom probe technique was used to observe the three-dimensional solute distribution around the extended edge dislocation in neutron irradiated austenitic stainless steel. The segregation of Si, Cr and Ni to stacking fault (SF) was observed. Solute segregation to the SF was larger than that of the Shockley partial dislocation. The behaviour of the segregation involves both Suzuki segregation and radiation-induced segregation (RIS). However, the effect of RIS was stronger than that of Suzuki segregation in this study.Keywords: segregationdislocationaustenitic steels3DAP