In France, the dairy sector within the mountain areas turned strongly to a strategy of cheese production under quality signal like of differentiation, two strong disparities concerns the Agricultural Income differential per dairy farm per year; the other-linked to the previous disparity are getting older and fewer y shed light on the impact of economic and social performance one (PDO Cantal), few firms have taken control on the supply chain and have chosen with the time a model based on costs leadership, imposing low milk price at farm gate. The second one (PDO Comté) is a specific model with a strong and structured collective a these two models have an impact on the dairy farms economic for the PDO Comté case, some business companies (farmers and their cooperatives which are agro-food processing firms), related within a achieved to control for the better the rules which govern the PDO cheese production chain. This collective action in Jura Mountain and its market power benefit to farmers thanks to the better milk price at farm gate than in others mountain areas. Thanks to data FADN (survey concerning European Network for farm accountancy)and data from the French Agricultural Census 2010, we bring to light the main factors of explanations of the highest economic and social performance ofthe dairy farms. The substantial Agricultural Income per farm is due to the substantial Gross Output. This extra Gross Output is partly saved: - to increase the farm size and to organise regrouping of lands; - to increase the herd and therefore the production; - to develop technologies and assets. These numerous actions have strongly carried farmers to develop new skills, to increase the labour productivity and to ensure greater the renewal in dairy farms. This evolution has begun for few decades.