The purpose of education of propositional logic is to understand the basic structure of the mathematics and to improve the logical thinking in normal life. But in the seventh curriculum, some basic terms, for examples $wedge$ and $vee$, are not introduced, the proposition $p{\rightarrow}q$ is not defined properly, and use the wrong term $Rightarrow$ so that it is difficult to understand the propositional logic. In this paper, we present a suitable content for the propositional logic in high-school mathematical class. We also present a proper definition of the proposition $p{x}{Rightarrow}q{x}$ without using the notation $ ightarrow$. We finally give proper definitions of necessary conditions, sufficient conditions, and necessary and sufficient conditions.