Dissertation for post-graduate degrees is an organic whole,a logical system com-posed of a series of concepts and propositions.In dissertation writing,postgraduates need to establish a sense of system.This kind of system consciousness is embodied in clarifying re-search questions and anticipating competing viewpoints in conceiving,defining core concepts and forming a tree-like conceptual system in writing,and clarifying one's own knowledge contribution and building a pyramid-like dialogue structure in revision.