This dissertation discusses the evolution of one subsystem under local operation on another entangled subsystem and derives a general formula of the evolution under the ps operation ( postselection ) on another entangled subsystem 这些能影响另一个系统的操作就是ps操作(不完备的测量操作) ,并得出了在一系统的ps操作下,另一个系统转换后的约化态。