Lithium containing alloy systems are in the focus of many studies as potential electrode materials for lithium ion batteries (LiBs). However, the tremendous volume changes during the lithiation prevent a common application of these materials in nowadays used batteries. Nevertheless, the ternary Li–Sb–Sn system is considered as promising electrode material, as the binary compound SbxSn1-x shows a relatively high rechargeable capacity. Therefore, we investigated the phase relations of this system experimentally, in order to understand the lithiation pathways during charge and discharge process. Two isothermal sections in the Li–Sb–Sn system at 300 °C and 400 °C respectively, have been studied by 50 samples applying powder X-ray diffraction (PXRD). It has been shown, that SbSn can uptake up to 15 at.% Li, without changing the corresponding crystal structure. Beyond, the Li-rich compound Li3Sb forms with simultaneous precipitation of liquid (Sn). The ternary phase, Li8SbxSn3-x, earlier published by same authors, has been confirmed.