This study is proceeded with Symbol Analysis Method and KJ Method to proceed 129 documents about Graphic Symbol and Subject Application Analysis of Global warming poster samples. It is divided into two parts: (1) Research of symbol analysis and metaphor of poster image. (2) The performance issue and subject analysis of environment protecting poster design. Extract 8 groups of altogether 12 to proceed and discuss metaphor technique of symbol as well as the reference relation between topic and vehicle, and be aimed at metaphoric composition principles of image to analyze the graphic relations among Target Space, Source Space and Blended Space. According to the subject of performance to take other 129 compositions of poster samples be sort by KJ Method. The result of the reasearch discovered that metaphor the technique and the type "topic and vehicle mixes by the main body" the work number of articles are most, The next best is "topic and vehicle juxtaposition" as well as "topic and vehicle appearance", and the least is "topic appears with the vehicle hideaway". The reason is that some medium is used to come the metaphor to symbol warming subject in warming poster. And designers habitually use vehicle medium to come the metaphor to perform the subject; while the performance subject by polar bears' image and plants, earth and map take the majority. The reason lies in that polar bears easy metaphor to leave the indication of the melting-ice in north pole and the extinction of creatures; chop plants metaphor to leave the environmental protection and the warming problem; the earth and the map state directly global or the region effect phenomenon that causes by the warming. These three themes are the easiest to express this warming subject, therefore the percentage are quite many.