One of the key issues in collective action is whether stakeholders are able to realize commons governance through a trust-based mode or control-based mode. This paper, examines whether trust and control affect the commons governance for small-scale irrigation facilities, and the moderating effects of group size on the relationship between trust and control and cooperative performance. The data were collected from 504 households who participated in the collective action for small-scale irrigation facilities in Shaanxi, Gansu Province, and Ningxia Hui Autonomous Region of Northwest China. The analysis was performed by Structural Equation modeling and hierarchical regression. The findings show that trust and control are contrasting forces that influence the participation degree and the cooperative performance, although their relationship is not of a simple supplementary character but could be moderated by the group size. Both trust-based and control-based modes of irrigation management are effective in small groups, whereas only a control-based mode of management has an effect in big groups. The theoretical contribution of this paper clarifies the mechanisms through which the contrasting forces of group size are exerted on trust and control, directly and indirectly influences the participation degree and the cooperative performance in commons governance.