Abstract: AutoCAD is an open computer aided design system. The system running environment is set through its system variables. When users need exploiting the system, some related system variables in application program should be set under the necessity of applications. In fact, it's difficult for users to master the commonly used system variables. By studying AutoCAD system variables, a technique of automatic tracking system variables in AutoCAD2006 is put forward, and a Visual LISP program of automatic tracking system variables was written. The experiment shows that the program can track all system variables in AutoCAD2006. The resource codes of Visual LISP were given, and its principle and usage were described in details. A applied tool was provided for AutoCAD exploitation users.

Key words: AutoCAD, System variable, Visual LISP

摘要： AutoCAD作为开放的计算机辅助设计系统，其系统运行环境由系统提供的系统变量来设置。用户在使用其进行二次开发时，需要在应用程序中对相关的系统变量进行设置。在实际应用时，经常出现的系统变量较难掌握的情况。通过对AutoCAD系统变量的研究，提出了一种在AutoCAD中自动跟踪系统变量的技术，并采用其内嵌的Visual LISP语言编写出了系统变量自动跟踪程序。通过实际测试，能够对AutoCAD2006版的全部系统变量实现自动跟踪。给出了Visual LISP源程序代码，详尽介绍了其程序原理及使用方法。对于应用AutoCAD进行二次开发与辅助设计的用户提供了一个实用的辅助工具。

关键词: AutoCAD, 系统变量, Visual LISP