The aim of the authors is to give some precisions about the relationship between the cycle of Echinococcus multilocularis and the dynamics of the different potential hosts (rodents and carnivorous) existing on the area under study (Sept-Fontaines, Doubs, France), by analysing the results of rodents trapping operation (mainly on Microtus arvalis) some of it are infested by the parasite. For this purpose they include the parasite in a prey-predator system and show how the behavioural pattern of the different species involved in the system (in one hand, the predator, Vulves vulpes, infested by the adult form of the parasite, in an another hand the prey, different vole species, infested by larvae) allowed a regular circulation of the parasite between rodents and foxes. In the view of increasing our knowledge about the dynamic of parasite transmission they propose an ecological approach which should allowed to realise a real epidemiological study. In the described process the diversity of habitats had been taken into consideration and play a fundamental part.