This study aims to determine (1) the interaction between various types of local rice plant varieties and various kinds of irrigation systems on mycorrhizal fungal activity, (2) to find out the best local rice varieties in mycorrhizal fungal activity, (3) to find out the best irrigation system on mycorrhizal fungal activity. This research is an experimental research arranged by compiled using a Uncompletely Randomized Design (RAKL) with a 4x3 factorial strip plot design with 3 replications approach. First Factor is a variety of local rice plant varieties consisting of four treatments, videlicet : early Rojolele varieties (V1), Mentik Wangi varieties (V2), Mentik Susu varieties (V3) and Black Cempo varieties (V4). Second Factor is a type of irrigation consisting of three treatments, namely: Conventional irrigation (A1), irrigation 10 days inundation 5 days dry (A2), irrigation 7 days inundation 3 days dry inundation (A3). Observation parameters consist the number of spores, percentage of infection in roots, observation of MVA organelles, root length, root polyperation, root fresh weight, root dry weight and grain weight per clump. As the result, it indicates that the dynamics of the best varieties of Mycorrhizal populations are Mentik Wangi and Mentik Susu with 10 days of irrigating 5 days dry. Cempo Hitam is the best root variety during the development and with 10 days of irrigating 5 days dry. The best varieties of the rice plant varieties, Mentik Wangi, were irrigated 7 days inundated by 3 days dry.