We have fabricated MgB2 superconducting tapes with a powder-in-tube (PIT) technique using Mg(BH4)2 precursor. Heat treatment decomposes Mg(BH4)2 and subsequently forms MgB2 as nearly single phase. Although the tapes carry supercurrent at 4.2 K and 0 T, the transport critical current (Ic) values of the tapes decrease down to 0 A by applying a magnetic field as small as 1 T. This is due to the weak grain coupling brought about by the large reduction in volume at the formation of MgB2 from Mg(BH4)2. On the other hand, the use of the intermediates obtained by the calcination of Mg(BH4)2 powder successfully improves the critical current density (Jc) property close to the level of tapes using conventional Mg + B powders, owing to the suppression of the reduction. The insufficient purity of the starting precursor and the high sensitivity of calcined powder to oxygen and moisture prevent further improvement in the Jc property.