The comparative approach offers a particularly rich prospect for the study of textbooks, which are very complex objects. At first glance, one would think that they are simply the result of political choice and values of the country in which they are produced. But they are also determined by the evolution of knowledge in History, and by epistemological and ideological considerations. This article deals with the conditions of the comparison of textbooks, and proposes an approach combining quantitative and qualitative method. Using the example of the Berlin blockade, we also give some first results that lead to question the place and use of pictures in the history textbooks.