A fuzzy logic-based decision model application has been developed to monitor the progress of creating green cities in Indonesia. The model utilizes the main method of fuzzy slope and multi-stage analysis, considering six categories including electricity, water, air quality, building land, transportation, and waste management. This application effectively evaluates the green city score. It is well-suited for implementation by the Ministry of Environment (Kementrian Lingkungan Hidup) to assess the level of environmental friendliness in all cities and establish environmental regulations throughout Indonesia.