The properties of dark soliton train in distributed amplification and transmission system are studied. The results show: in distributed amplification transmission system, the properties of dark soliton cascaded by odd and even number dark solitons are different, train transmission of dark soliton train cascaded by odd number dark solitons is stability, but train transmission of dark soliton train cascaded by even number dark solitons is instability, there are apparent soliton self-frequency shift and deformation of soliton caused by interaction among dark solitons.