High　performance　thermoelectric　materials　are　required　to　possess　multi-valley　electron　transport　characteristics.　However,　this　may　risk　causing　strong　inter-valley　scattering　and　exponentially　decreased　carrier　mobility　with　respect　to　temperature.　Herein,　taking　indium　telluride　as　an　example,　we　reveal　that　such　effects　could　be　effectively　suppressed　via　introducing　minute　antimony　phases　(1-2　mol%),　which　successfully　convert　the　predominant　scattering　mechanism　from　inter-valley　scattering　to　acoustic　phonon　scattering　at　high　temperatures.　Finally,　with　the　noticeable　improvement　in　both　carrier　mobility　and　power　factor,　a　maximum　zT　of　0.8　is　achieved　in　the　InTe-Sb-0.01　sample　at　623　K.　The　proposed　strategy　of　suppressing　inter-valley　scattering　by　nano-precipitates　should　be　one　of　the　possible　solutions　to　such　issues.