1. A method of automatically generating a summary for a textual document, comprising: segmenting a given textual document into document segments, wherein the document segments are words, sentences or paragraphs in the textual document; extracting a number of document segments to form an initial summary for the document; for each document segment in the initial summary, calculating the correlation degrees between this document segment and its neighboring document segments, wherein the neighboring document segments of a given document segment refer to the document segments within a predefined distance from the given document segment; and adding the neighboring document segments with higher correlation degrees into the initial summary.