The ideology of Heidegger intends to explore the "thinking" forgotten by human beings,to make a detailed inquiry to the existence of the "thinking" and to clarify the thinking sheltered by things."Clarify" refers to disclose the thought from covered to uncovered situation.During the process,it reflects the transferring "thinking" from "cover" to "uncover" or from "overt" to "covert".The paper focuses on the exploration towards the thinking of "covert" and "overt" in the shelter to uncover,especially the "uncover" in "covert".