Abstract: Based on the cost-benefit data of 306 mutton sheep breeding farms （farmers） in 17 cities of Shandong province, which was obtained by questionnaire survey, this paper uses SPSS 22.0 quantitative analysis software to calculate and confirm the moderate scale of mutton sheep breeding of corporatized breeding farms （farmers） and large-scale breeding farmers in Shandong on basis of breakeven. The results show that breakeven can be achieved only when the mutton sheep breeding scale of corporatized mutton sheep breeding farms in Shandong are 529 to 2 406, and the profit can be maximized when the mutton sheep breeding scale is 1 467; breakeven can be achieved only when the mutton sheep breeding scale of large-scale mutton sheep breeding farmers in Shandong are 40 to 394, and the profit can be maximized when the mutton breeding scale is 217.

Key words: moderate-scale breeding, breakeven, mutton sheep, Shandong province