The land use function (LUF) concept is a useful tool in assessing sustainable development. With the goal of exploring the conceptive difference of policy makers and local farmer on LUFs and understanding the capacity of different land use types to provide LUFs, we used a participatory method to assess LUFs in Guyuan, which included four phases: literature review and field surveys; specification of the LUF context; ranking of priorities and weighting of LUFs; and visualization and discussion of the results. It was found that policy makers perceived regional problems and critical LUFs well, whereas farmers had a clearer perception of local issues that affect their livelihood. For policy makers, environmental functions had a higher priority than economic and social functions; in contrast, farmers prioritized economic and social functions. However, based on the perception of both groups, the result was the same whereby environmental functions had the highest LUF value and economic functions had the lowest. Participatory assessment methods enhanced our understanding of causal linkages between land use and LUFs, and may help stakeholders improve future land use decisions and management for regional sustainable development.