<em>Agrobacterium</em> sp. I26 and <em>Agrobacterium</em> sp. I30 are bioremediation agent that can be used as functional bacteria in biofertilizers. The storage of these bacteria requires carrier. Not all carriers can support bacterial viability, so it was necessary to examine carrier formulas as basic ingredients for biofertilizers which the quality standards based on the Minister of Agriculture Regulation No. 70/2011. This research aimed to: (1) study the viability of <em>Agrobacterium</em> sp. I26 and <em>Agrobacterium</em> sp. I30 in some carrier formulas; and (2) obtain the best carrier formula to support the viability of <em>Agrobacterium</em> sp. I26 and <em>Agrobacterium</em> sp. I30. Research design was factorial using completely randomized design (CRD) as the based design, consisting of 2 factors: 1) Carrier Fornula (C): C1; C2; C3; C4; C5, 2) Bacteria (I): I1; I2; I3, so there were 15 treatment combinations each was repeated 4 times, thus there were 60 experimental units. The results showed that <em>Agrobacterium</em> sp. I26 has better viability than <em>Agrobacterium</em> sp. I30 during 90 days incubation period. The best bacterial viability with total bacterial as the indicator was C4 carrier formula: 74 x 10­¹³cfu.g^-1 for <em>Agrobacterium</em> sp. I26 and C3 carrier formula: 155 x 10¹² cfu.g^-1.