Regarding changes in French and British labour market as in their educational system since the Eighties, one may address the evolution of their labour market segmentation. Is the predominance of Internal Labour Market in France and Occupational Labour Market in Great Britain (Eyraud, Marsden, Silvestre,1990) still relevant ? We propose a more complex segmentation of labour market with four segments based on tenure, labour mobility and their wage return to account for nowadays situation. Empirical investigations we carried out are based on national labour surveys (Enquête Emploi for France, LFS and GHS for Great Britain). In this paper we expose first investigations and explain which further methods we propose to use in order to characterise French and British labour market segmentation.