Abstract The study about “Inoculation of Mycorrhizal Arbuscula Fungi in Several Doses and Time Variation of Phospatase to Banana’s Seedling Cultivar Jantan” had been conducted from October to April 2011 in Plant Physiology and Tissue Culture, Department of Biology, Faculty of Mathematic and Natural Science and Green House of Agriculture’s Faculty, Andalas University. The study used Completely Randomized Design in factorial with three replication. The first factor (A): A0 (without inoculation), A1 (5 g inoculan FMA PU 10), A2 (10 g inoculan FMA PU 10), A3 (15 g inoculan FMA PU 10), A4 (20 g inoculan FMA PU 10). Whereas the second factor (B) : B0 ( 0 day after inoculation), B1 ( 10 th day after inoculation), B2 ( 20 th day after inoculation), B3 ( 30 th day after inoculation), B4 (40 th day after inoculation). The result showed that no significant effect of treatment statistically to increased the height, leaves number, diameter and dry-weight of plant. The level of Phosphor is about 0,2272 %- 0,9627 % while the level of Kalium is about 1,4 % -2,2456 %. Criteria of root infection is middle – very haigh. Commonly, the seedling of banana cultivar “Jantan” depends on inoculation of FMA with criteria less-middle.