The 11th Five Year Plan has divided national functional zones in the basic unit of county-level administrative region.After implementation of national Major Function-oriented Zones (MFOZ) at prefecture and county levels,the spatial development sequence must be specified,development intensity must be limited,oriented zones must be designated and “red line” areas of spatial governance must be defined.In view of the above,choosing a typical county area and exploring its functional zoning after orienting its major functions will supply reference for carrying out the national spatial planning in the 12th Five Year Period,and it will also provide experience for the study of function regionalization which is the theme of MFOZ in the present academic circles.In this paper,the authors take Shangyu County as an example to study the general principles,train of thought of county-level functional regionalization in development-optimized areas,and to explore its reasonable functional zoning plan.Consequently,the authors present five principles and suggest a function-oriented zoning plan with 2 levels and 4 types. The 11th Five Year Plan has divided national functional zones in the basic unit of county-level administrative region. After the implementation of national Major Function-oriented Zones (MFOZ) at prefecture and county levels, the spatial development sequence must be specified, development intensity must be limited, oriented zones must be designated and “red line ” areas of spatial governance must be defined.In view of the above, choosing a typical county area and exploring its functional zoning after orienting its major functions will supply reference for carrying out the national spatial planning in the 12th Five Year Period, and it will also provide experience for the study of function regionalization which is the theme of MFOZ in the present academic circles .In this paper, the authors take Shangyu County as an example to study the general principles, train of thought of county-level functional regionalization in development-optimized areas, and to explore its reasonable functional zoning plan. C on played, the authors present five principles and suggest a function-oriented zoning plan with 2 levels and 4 types.