War posters published during the I & II World Wars

War posters have always been the most important weapon of the fighting nations during World War I and II. Because wartime propaganda has got the most important role to make people adjust to abnormal conditions, and adapt their priorities and moral standards to accommodate the needs of war. Influencing the beliefs or values of others is the primary purpose of propaganda. Propaganda posters are one format that has been used throughout history to influence the opinions of groups of people. To achieve this, graphic designers have often represented warfare by using conventional visual codes already established in mass culture. In this study, How these conventional visual codes are established in different countries and the effects of these establishments on societies will be discussed thoroughly. And also it is the most important thing that how posters succeed to motivate the people for joining into the army to kill other nations, women's entry into the workforce with bluring the negative aspects of war because of the influencing of these war posters, all women believed in themselves that they could do all the work. Some of the war posters tried to convince the people by showing the pictures of people who want to travel and see new places. To sum up, when we have finished discussing about the war posters and their effectiveness, it will be clear that all that is done in different cultures and languages is for the same purpose, considering similarities, differences and relationships between the slogans and elements in design. Key Words: War Posters, I & II World Wars visual documents