Encouraging farmers to protect their environment is of great significance in improving watershed ecological environments and promoting the sustainable development of the watershed economy. To explore the factors influencing farmers' ecological protection behaviours in the river basin, we constructed a structural equation model to analyse the survey questionnaire responses of 719 farmers in the Wei River Basin, Shaanxi Province, China. The theoretical framework incorporated farmers' watershed belonging and social capital into an extended value-belief-norm model. Robustness tests revealed that incorporating these variables was valid. Personality norms, watershed belonging, and social capital all had direct positive effects on farmers' watershed ecological protection behaviour. Value orientation, environmental concern, consequences awareness, and responsibility attribution influenced the next variable in a causal chain and finally acted on watershed ecological protection behaviour indirectly through personality norms. Farmers' watershed belonging and social capital positively impacted individual norm; through this, there was an indirect positive impact on their watershed ecological protection behaviour. Moreover, watershed belonging and social capital reinforced each other.
