There is provided a method and computer system for object persistency that includes: running a program; storing an object of the program into a random access memory in response to determining that the object is a non-persistent object; and storing the object into a phase change memory in response to determining that the object is a persistent object. The method and computer system of the present disclosure do not need separate persistency layers, such that the programming model is light weighted, the persistency of object data is more simple and fast, and implicit transaction process is supported, thereby a great deal of development and runtime costs are saved.