(Not controled OCR) The French King scallop farming method (hatchery, intermediate culture in cages nnd sea-bed extensive ongrowing) has been developed since 1983. A multi-steps project analysis has been carried out to estimate the economic feasability of the rearing activity. Because there is no market for spat in France at the moment, the project concerns the whole production cycle from hatchery to harvest. The project is designed to supply 150 m.t. of maketable scallops, which is the expected French farmed production in the near future. The project analysis software developed by IFREMER provides the main financial criteria, i.e. internal rate of return, potential earning power, cash requirements and a breakdown of the production costs. The first simulations allow us to expect the French scallop farming activity being profitable, but much attention has to be given to the cash position because of the lack of income during the first years. Broadly speaking, whatever the rearing strategies are, it turns out that a survival rate of 30% after sowing is required to expect economic feasability when the ex-farm price of the scallop is about 3.6US$/kg.