Abstract: In order to evaluate, monitor and examine the level, process and efficiency of developmental sustainability of ecological demonstration area, a set of quantified indicator system and three types of mathematical methods (such as indices weighed coupling method, efficacy target value method and fuzzy comprehensive evaluation method)are constructed in this paper. Yuexi County, one of the 3rd national ecological demonstration areas is taken as a case study. The values of developmental sustainability for the integrated system and three subsystems (economic, natural and social) in datum year (2000), near future year (2005) and long-term target year (2010) by above indicator system and mathematic models are dovetailed to the present condition and future trend of this study area. As a result, this pilot research will be valuable in enriching the quantified theory of ecological demonstration area and guiding construction practices of Yuexi County's ecological demonstration area.

Key words: (]ecological demonstration area, development sustainability, indicator system, mathematical model, Yuexi County