According to the number of environmental management practices implemented by the firm and the degree of integration of environmental management with other functions of the firm, this study divides environmental management into two dimensions: environmental management breadth and environmental management depth. We argue that the impact of environmental management breadth on manufacturing performance is moderated by environmental management depth. A survey data including 225 Chinese manufacturing firms is used to test the hypotheses. Results show that there is an inverted U-shaped relationship between environmental management breadth and manufacturing performance; the impact of environmental management depth is positive; meanwhile, environmental management depth moderates the relationship between environmental management breadth and manufacturing performance.