The rapidly expanding urban areas of the world constitute an environmental challenge for the 21st century that requires both new analytic approaches and new sources of data and information. Ecological Planning with multi-criteria decision making is a process that evaluates the alternative land uses in relation to its environmental and socioeconomic surroundings, with the purpose of manage the natural resources, preserve the ecosystems and solve or diminish possible environmental conicts. The objective of this research is to determine an ecological capability of urban development by using Fuzzy Logic Model (FLM) in GIS and IDRISI environments for the south zone of Centeral Alborz. This evaluation incorporated ecological factors in the region, such as physical factors (Topography, Elevation, Slope, Soil, Geology, Precipitation, Temperature) and biological factors (Vegetation density and Conservation areas) affecting in urban development land use. First, Urban land-use was categorized according to the classes of ecological word model in Iran, such as suitable, relatively suitable and unsuitable. Then, Multi-Criteria Decision Making (MCDM) was performed to evaluate ecological suitability of the development for each class, according to appropriately measured and weighted factors and a suitability map for the classes was developed using an algorithm that combines factors in the integrated fuzzy method of Weighted Linear Combination- Analytical Hierarchy Process (WLC-AHP). The results indicated that MCDM with FLM has high functionality for environmental evaluation of urban development .