Until recently it was admitted that the pressure debitage technique had been invented at the end of the Upper Paleolithic, and its prescence in different geographical zones was difficult to explain. Now that we are able to recognize it thanks to advances in experimentation, its invention seems to have been made some 20,000 years ago in the vast area where the Mongoloid people, who were to occupy the Far East, the Beringian zone and America, first appeared. We are going to describe the methodological approach which allowed us to imply pressure debitage as a cultural marker in the history of prehistoric penetration into North America and to show the specificity of this technique in the Paleolithic of North Asia. Our proposal is a development of an unpublished paper presented at the Novosibirsk Symposium in 1990. The opportunity we had then to examine lithic industries from Siberia convinced us of the early use of the pressure technique.