Abstract: The present invention relates to a method and system for establishing tree file structure in a computer. The method executes the following steps: the computer invokes a panel generating program to establish a panel for displaying a tree structural of a file while it opens said file; said program invokes a file tree generating subprocess, and adds a file node corresponding to said file into said panel, wherein the displaying content of the file node is the file title of the file; said subprocess takes said file node as a root node and generates the tree structure of said file in said panel. The method can display the information of the opened files and documents, and display the relation between them so as to support the switching between the windows of each application document and avoid occurring improper operating. The system includes a panel creating module, a file node adding module and a tree structure generating module.