Sustainable development has gradually and over time brought about various approaches with different goals. Ecological city is one of these approaches that has a stronger emphasis on environment issue as well as the relationships between city development and nature. The purpose of this study was to determine the local factors effective on the achievement of ecological city in order to sustainably develop Darcheh city. This study was mixed-methods (qualitative-quantitative) in terms of paradigm, and descriptive-analytical and exploratory in terms of nature. Data was collected using document analysis and field study through two means: interviews with experts using the Delphi method and a questionnaire. In the qualitative phase (the Delphi method), 30 experts and specialists were interviewed. In the quantitative phase, the statistical population of the study was comprised of Darcheh citizens aging over 15, who were 37367 individuals in the year 2016. From among these, 375 participants were selected using cluster sampling. The face validity of the questionnaire was confirmed by the urban planning experts, and its reliability was corroborated through Chronbach’s alpha coefficient. The results of the study in both phases (qualitative and quantitative) showed that the environmental and economic dimensions – with the average scores of 4.23 and 4.11 and (beta) regression coefficients of .345 and .349 – best describe the achievement of ecological city, there is a relative homogeneity among various neighborhoods of the city in terms of ecological city indices, and the ecological city development can be attained through a clear model. Moreover, according to Pearson correlation coefficient, the citizens who have had a higher educational level have shown a higher tendency (.585) to help implement the ecological city project.