More and more, vocational training is considered by public action to be the key resource in order to achieve the objective of integration of people in difficulty on the labour market (Guitton 1998, Lallement 2006). The strategy consists of making the development of human capital and of individual qualifications the principle tool to improve job security and to make workers more competitive on the job market (Gazier 2006). Vocational training is considered a crucial resource to decrease exposures to unemployment and to equip people with durable and recognizable resources. This contribution proposes to analyse the role of the training policies into the process of socio-professional insertion of the immigrants into the regional (PACA) labour market. A qualification could represent an opportunity to integrate a productive sector, but it could also be seen as a « career mobility chance » (Zucchetti, 2000) which catalyses the working status evolution of the immigrant (from an “informal” employment to a regular one; from a dependent position to an entrepreneurial activity etc.). However, if a strong link between vocational training and professional insertion policies is visible, it is difficult to find, within the public action, a clear connection between vocational training and the immigrants policies. Does it deal with a French specificity in the political formalisation of problems, that ignores ethnic categories (Guiraudon 2006, De Rudder, Poiret, Vourc'h 2000)? Or are the immigrants conceived as a non-qualified workforce which supplies to sector needs, where qualification doesn't play a fundamental role (Gélot and Minni, 2006)? The case of the construction sector seems to be revealing: what is the relevance of the immigrant workforce in PACA? What kind of socio-professional insertion does the sector offer to the immigrants? What possibilities of ascending mobility do immigrants have? What kind of “integration through work” (Castel 1995, Paugam 2000) is accessible to the immigrants employed in this sector? We focus on the construction sector case through the analysis of the branch policies and of the instruments of actors (Lascoumes et Le Galès, 2005) at a local level, in order to define the specificity of the sector needs and of its vocational training offer. At what level the “immigrant issue” plays its hand and becomes an observable element of the local debate? Are immigrants the recipients of specific actions or are they concerned by general policies aimed at the resolution of the qualification needs of the sector? The contribution will propose some interpretations to be discussed.