We prepared melt-textured YBCO with CeO2 addition in order to enhance flux pinning. SEM photographs showed that Y2BaCuO5 precipitates oi about 1μm size were uniformly distributed in YBCO grains. Magnetization hysteresis at various temperatures was measured to investigate critical current density using a SQUID magnetometer. Critical current density at 77 K in a field of 1 T was about 2 x 10^4 A/cm^2 and increased by lowering temperature. The irreversibility line determined from the closing points of the magnetization hysteresis was shifted to high fields. The temperature dependence of the irreversibility field followed a power law, Hirr α(1 - T/T,)” with n ≈ 1.4.