Public service poster design is an important category of graphic design, covering graphics, text, color, layout and many other elements. Graphics play a very important role in public service posters determining whether messages can be effectively delivered to the public or not. Holger Matisse, a famous contemporary international visual design master, once said, "a good poster should be annotated and explained by graphic language rather than just graphic words. Public service poster design, to some extent, is graphic design. This study analyzed graphic representation of 100 Chinese public service posters that received poster design award from international exhibitions from 2016 to 2018. The results of this study showed that indirect expression and abstract graphic expression are effective in delivering messages to the public.