In French: Elements pour la cartographie ecologique des populations de Rhipicephalus du groupe sanguineus (acariens, Ixodoidea) dans l agglomeration marseillaise, en relation avec les diverses formes d urbanisation. - The epidemiology of Mediterranean spotted Fever (Boutonneuse Fever) in the French Mediterranean towns is linked with the populations of Rhipicephalus sanguineus, which is both vector and the reservoir of the disease. In order to localize the tick populations, the area of Marseille was first divided into 11 zones according to the various types of buildings (fields use, forests, waste lands, gardens). The 300 dogs were examined from five veterinarian practices. The ticks were picked up, identified, and the owners questionned about the annualleve1 of infestation of the dog by ticks. On the other hand, R. turanicus was investigated in the same zones by the flagging method. The main results of this study are: - R. sanguineus (s., str.) has a very large distribution in the various type of urban development. Dense centers of housing are however much less favourable for the tick than scattered ones. In the favourable zones, the different types of habitats are not equally propitious for the species. Houses with gardens are the most suitable biotopes. The environment of large buildings is less propitious. The other ticks of the sanguineus complex (R. turanicus, R. pusillus) are rather scarce and more usually found in the outskirts of the town. The large increase of the suitable habitat (houses with gardens) in the outskirts of Marseille could be a reason for the increasing incidence of Mediterranean spotted Fever in the town.