Agam regency is one district in West Sumatera which is 38,20% of its population work in agriculture sector. The government of Agam greatly promotes the development of the agricultural sector with the development of institutions and commodities of every farmer group. Counseling for each farmer group conducted by counselors and managed by the Agency for Agricultural Extension of Fishery and Food Security (BP4K2P). With the number of farmer groups of approximately 1737 groups and spread over 2,232.30 km2 will make it difficult for BP4K2P especially extension workers to know the location of each farmer group. A farmer group-based information system becomes a solution in finding information for each farmer group. Waterfall model is used as software development life-cycle in this research. Its built from sequential process sequences that cover the stages of analysis, design, coding, and testing. Analysis obtained the functional requirements of the system is formulated with the ability to search by name of farmer groups, districts, type of groups and commodities and display the route to the location of farmer groups. The application is built on the web using Google Maps as the base map. Spatial data processing utilizes PostGIS features. System testing is done with blackbox testing that focuses on the functionality of the system. The results of tests conducted by seven testers on the 7 functional requirements indicate that the system built has been in accordance with the functional requirements of the system designed.