ABSTRACT The appropriate sizes of scale-breeding industries are causing increasing attention in that rational scale-breeding industries may both meet the meat demand of the market and avoid serious environmental problems. In this paper, the appropriate scales of breeding-type family farms were studied from the perspective of quantifying resource losses. The mathematical models about quantifying resource losses were built, and then the evaluation index system of resource losses was established. More than one hundred family farms in Sichuan province and Chongqing city of China located in the subtropics were selected as research cases and were classified as small-, medium- and big-scale family farms, whose unit resource losses and resource loss rates were both evaluated by the index system. Results show that the unit resource losses and the resource loss rate of medium-scale family farms are the lowest among these three kinds of family farms. Therefore, medium-scale farms are moderate, and then are recommended for scale-breeding industries.