In this paper, we briefly summarize the applications of deductive logic in knowledge engineering, and analyse the limits of it in knowledge representation, reasoning, problem solving, logic programming and as the specification language and analysis tool of expert systems. 本文简要归纳了演绎逻辑在知识工程中的作用,着重分析了演绎逻辑在知识表达、推理、问题求解、逻辑程序设计等方面以及作为专家系统说明语言与分析工具的局限性。