戰爭海報主要是政府對普羅大眾提供戰爭相關資訊的媒介，並未因其張貼處只在街角、公共場所或工廠角落而降低設計的要求與品味；相對的，在總體戰爭的動員下，許多藝術家及設計家們，被政府徵召進行戰爭海報設計的工作。由於海報是最能表現設計者豐富想像力與視覺效果的媒體，而且海報主要藉圖像符號來傳達訊息及意象，使戰爭圖像符號成為戰爭海報重要的視覺語彙。 美國二戰海報中常用的戰爭圖像符號包涵：一、美國意象圖騰中的星條旗、羅斯福總統、山姆大叔及自由女神；二、軍事與國防意象中的武器、軍人、殞落之星與「V」勝利符號；三、敵國與威脅意象中的敵國首領、敵國國旗與國徽以及邪惡生物中的蛇與老鼠；四、其他如十字架和鉚釘工羅西。這些戰爭圖像符號明確表達了美國立國精神與價值，其素材結合了歷史傳統與文化，並且以美式幽默的創意呈現。 由於這些戰爭圖像符號不少由民間廣告界參予設計，使美國二戰海報中的戰爭圖像符號運用充滿了創意與活力。我國近年來為凝聚國人堅強抗敵意志及建構全民國防信念與價值而舉辦各項海報徵集活動。美國二戰海報對戰爭圖像符號的彙整、轉化與靈活運用，值得我國參考。

War posters are the medium of war information provided by a government to the general public. Their styles and tones in delivery are constant factors despite they may be posted up around dark corners or transient public spaces. In fact, based upon the mobilization need for a total war in the WWII, there were many designers and artists called up by governments at war to the effort of war propaganda. These professionals were recruited because it is through their rich imaginative works and the visionary effects created that war posters became one of important textual tools, capable of sending powerful iconic messages in images and symbols to the targeted populations. This paper collected four types of US war posters issued during the WWII, including (a) idealist images such as stars and stripes of American national flag, President Roosevelt, Uncle Sam and the Statue of Liberty; (b) military icons such as weapons, soldiers, fallen star and the ”V” sign; (c) derogatory representations such as leaders, national flags, national emblem of the confrontational countries at war with the US, linking them to evil creature like snakes and rats; (d) symbols such as the Cross and Rosie the Riveter. An in-depth analysis by this paper showed that as a result of social participation from the advertisement sectors that had integrated in their works the traditional culture in history and American humor in reality, these US war posters were filled with initiative and animation that proved successful in delivering potent messages to the audience. With these findings, the paper subsequently argued that the US effective iconic approaches in war posters may serve as a good reference point for Taiwan to stimulate civilians' value on national defense.