Transport critical current density Jc and hysteresis loop at different field-sample orientations were measured for both melt-textured growth (MTG) and sintered YBa2Cu3Oy (YBCO) sample. Very high Jc (78K, 0 Oe) of 3.5×104A/cm2 has been obtained for the MTG YBCO sample. The experimental results show strong evidence of that the high Jc in MTG YBCO results mainly from the significant reduction of weak links because the bulk Jc for MTG sample are almost the same as the intragrain Jc for sintered sample. We also show that the Jc parallel to a-b plane is about an order of magnitude higher than that normal to a-b plane(Jc∥≈10Jc⊥).