根据已经公开发表的钱学森院士的讲话、文章和书信，在分析开放的复杂巨系统这个概念形成背景的基础上，重点考察了巨系统→复杂巨系统→开放的复杂巨系统的提炼过程，概括介绍了开放的复杂巨系统理论的基本内容，阐述了这个理论的形成对当前与今后的科学发展、尤其是对系统科学、思维科学-创新思维研究的重大意义。

On the basis of the analysis of the formation background of the concept “open complex giant system” in terms of the lectures, papers and letters published by Academician Qian Xuesen, this paper studies emphatically the abstract process of giant system → complex giant system → open complex giant system， introduces briefly the basic content of the theory of open complex giant system, and expounds that the formation of this theory has significance for development of science at present and in the future, especially for the investigation of system science, and noetic science—innovative thinking.