关键词: 线路分布表； 直达表； 转车表；

Abstract: This paper introduces a method of changing buses,and has a discussion of the changing buses principles. Matrix and simple calculation are used to build up mathematical model in the form of tables,and a strategy of changing buses is formulated.At last,four theorems are proved.

Key words: lines-distributing table； direct-reach table； changing-buses table；