This paper analyzed 32 years of public service advertising from 1981 to 2012 since it started. Periodization is made with the changes of regime. I researched this transition of topics and changes in the aspects of using languages through quantitative changes of PSA. In this paper, classification of Parent subjects complies with that of Korea Broadcasting Advertising Corporation and classification of sub-subjects is re-classified into 30 different results by analyzing the contents of advertisements. The subject of a public service advertisement reflects the transition by the political, social and economic changes. I investigated aspects in using language mainly by dialogues and narrations in the PSAs. Sentence is a total of 1,708 including both closing type and non-closing type(syntax). The public service advertising has higher proportion of closing type because it`s customers are people and should be courteous. What is most dramatic in the sentence types changes by the age is the proportional changes between imperative sentence and request sentence. In the early era, a lot of request sentence are used to request direct behavioral changes, but in the 2000s statements increased instead of request sentence. Statements with implied meaning are used with the wish that listeners do what speaker wants. The non-closing type(syntax) appeared as noun-type phrases, Tochi syntax, omitted syntax.