[ YBa_2Cu_3O_7-y ](123) powders were synthesized by the solid state reaction method using two different purity BaCO_3 powders (99.75% and 99.7% purity) and Y_2O_3 (99.9%) and CuO (99.9%) powders. The effect of BaCO_3 purity on the formation of a 123 phase and the superconducting properties were investigated. The mixtures of raw powders were calcined at temperature ranges of 800°C-880°C in air and finally made into a single grain samples by a melt processing with top seeding. It was found that a 123 phase was well formed at temperature above 870°C, but the purity effect on the 123 formation was negligible. The single-grain 123 samples prepared from the different BaCO_3 powders showed the same T_c value of 90.5 K and similar J_c values about 104;A/cm2 at 0 T and 77 K, and 103;A/cm2 at 2 T and 77 K. This result indicates that the low purity, cheap price BaCO_3 powder can be used as a raw material for the fabrication of single-grain, high-J_c superconducting levitator.