命题与开语句是两个容易混淆的概念 ,本文对这两个概念作一剖析 ,供读者参考 .1　命题、开语句的定义初中教材把命题定义为“判断一件事件的句子” ,高中教材把命题定义为“可以判断真假的语句 .”实质是一致的 ,即能判断表达的事实正确或错误的语句是命题 .开语句 :含有变量 , Propositions and open sentences are two confusing concepts. This article analyzes these two concepts for readers’ reference.1 Propositions and definitions of open sentences Junior high school textbooks define propositions as “judge sentences for an event”. Defining the proposition as “the statement that can judge true and false.” is essentially the same, that is to say that the fact that the expression is correct or wrong is a statement. Open statement: contains a variable,