A series of MoV_0.3Te_x (x = 0-0.4) catalysts were hydrothermally synthesized and tested for the selective oxidation of isobutane. Characterization results showed that their structure and properties depend on the composition of the prepared samples. Catalytic tests showed that relatively high conversion of isobutane (15.7%) and selectivity to methacrolein (42.1%) can be achieved over a MoV_0.3Te_0.3 catalyst. It is found that Te_0.33MO_3.33 (M = Mo and V) phase is active and selective for the selective oxidation of isobutane to methacrolein. In addition, isolation of surface vanadium sites would favor this reaction.