Abstract: The algorithm of Ant-Window^[1] is one of the important improvement of the study about ant colony algorithm.This paper defines big window and small window and points that the classical ant colony algorithm is the ant colony algorithm of big window essentially.The study demonstrates that the statistic average of Ant-Window’s diameter is 5 and that makes calculation complexity of narrow TSP problem down form 1/2（n-1）! to 5^n-1.

Key words: Ant-Window, diameter of Ant-Window, big window, small window, narrow TSP

摘要： 蚁窗^[1]算法是蚁群算法研究的重要进展之一。定义了大窗口和小窗口，指出经典蚁群算法实质上是大窗口蚁窗算法。研究表明，小窗口蚁窗直径的下限统计平均值约为5，使狭义TSP问题的计算复杂性由1/2（n-1）!降为5^n-1。

关键词: 蚁窗, 蚁窗直径, 大窗口, 小窗口, 狭义TSP