Hypereutectic Bi/Bi-Mn in-situ composites with ideal layer-separated and unidirectional growth structure can be prepared by a new solidification method,centrifugal unidirectional solidification,in the condition of proper rotating velocity of crucible and growth rate.The results showed that coarse fibrous MnBi compound was uniformly distributed into pure Bi matrix in internal layer of fracture.The mechanism of layer-separated growth and the factors influencing lay-er-separated were analyzed emphatically.