In the paper, we report the growth of Ge1-xSnx alloy by using combined sources of solid Sn and gaseous GeH4. In order to prevent Sn surface segregation, Ge1-xSnx was grown at a very low temperature that the decomposition of GeH4 is extremely slow. The growth might be stopped at some stage. For further investigation, digermane and trigermane are suggested to replace germane for the synthesis of Ge1-xSnx alloys by using combined sources.