A selection of papers from the International Colloquium Sciences and Empires - Comparative History of Scientific Exchanges European Expansion and Scientific Development of Asia, Africa, America and Oceania , held in UNESCO, Paris, April 1990. It raises some historical and epistemological problems related to the integration between classical science and modern science in countries with ancient scientific traditions; to the way modern science crossed cultural borders and took roots outside Europe; to the political strategies followed by European powers for their scientific expansion; and to the possibility of drawing a fruitful general frame for scientific development under colonial and imperial domination. It raises crucial issues about science in its imperial context. Scientific expansion has been a dimension of the sharing of the new world undertaken by European countries since the 19th century after the industrial revolution: which consequences such a context had on the way science was organized and developed outside Europe and which constraints this imperial system laid upon scientific activities and exchanges. This work explores a wide diversity of national situations as well as a variety of disciplines and institutions. It aims to contribute to a better understanding of contemporary problems of scientific development in the light of history of science.