The paper studies CCTV public service advertisements through multimodal discourse analysis based on the theory of Halliday’s systematic-functional grammar. It also analyzes the interactive meaning of CCTV ads. And the major findings are as followed. 

　　　Firstly, the audiences watch CCTV public service advertisements’ images through the eye contact, then understand that the images convey some information they contain.

　　　Secondly, the sound and the background music of CCTV public service advertisements supply a certain emotion. Such as the ad of father’s lies, father answers the phone from his daughter with a tired, lonely voice which shows he needs the daughter’s company.

　　　Thirdly, CCTV public service advertisements’ moving images also make contributions to the interactive meaning. The actions of the character, such as facial expression, gestures cause the attention from the different aspects. Thus CCTV public service advertisements’ maker makes the ads more persuasive through these aspects.