The Second World War has an enormous influence on Europe and the whole world. Germany attacked Poland on 1.9.1939 and the Second World War began immediately. After Warsaw was sieged and overcome, Nazi began a terrible regime there. German built a lot of Concentration Camps in Poland in order to reach the aim of genocide against Jews and Polish people. Paris was ruled by Germany and at the end of the war, Hitler commanded General Dietrich von Choltitz to level Paris with the ground, but General Choltitz did not obey the order. On the contrary, he saved Paris from the disasters. This article is focused on the suffering, development and influence of these two cities-- Paris and Warsaw during and after the Second World War. How they reacted to the German occupation and how they dealed with the after war problems. In addition, this article tried to gain an overview via analysis the terrible experience of the war, how the three countries-Germany, France and Poland tried to conciliate with each other and finally they are united under the ”European Union”.